Original Link: http://www.anandtech.com/show/2445
The MacBook Air: Thoroughly Reviewedby Anand Lal Shimpi on February 13, 2008 12:00 AM EST
- Posted in
Understanding the Ultra Portable
Before we get anywhere in this review, we have to have the talk. A friend of mine likes to call this talk a DTR, or Defining the Relationship. Usually with her it refers to something romantic but with the MacBook Air there are many similarities. It needs to be very clear what your expectations are of it and what sort of relationship you plan on having with the notebook in order to avoid something unpleasant.
Are you going home with it?
When Apple announced the MacBook Air, it was met with harsh criticism from many; it was almost as if the Air was being treated as the next MacBook Pro instead of an ultra portable Mac.
Let me give you an example. Back in college I needed a notebook to take to class with me that I could take notes on and email/browse with during class (not all lectures were as captivating as I’d like). Lugging even a 5-pound notebook around to class was a pain, I wanted something whose weight and form factor resembled its name; I wanted a notebook, something very thin, very light and just as easy as a pad of paper to carry around with me.
This wasn’t going to be my ultimate work machine, I wasn’t going to be running Photoshop on it, I just needed it to do some basic writing and web browsing. In many senses all I needed was a notebook-sized iPhone.
Since writing and basic internet access were the main duties of this machine, things like hard disk space, having an internal optical drive and absolute performance weren’t really concerns; running Notepad or TextEdit just doesn’t require much. At the same time, having a good keyboard, a killer form factor and keeping weight down were all more important than with a regular notebook.
Historically the ultra portable has been first and foremost, a very light notebook. The first ultra portables were around 3 lbs, but over the years we’ve seen entries into the space weigh in at less than 2 lbs. If you look at the weight of a textbook and remember how much you hated lugging that around in school, you’ll understand how even a 1 pound difference in notebook weight can make a big difference.
The weight side of an ultra portable is only one facet of importance, form factor is the other. This thing has to feel small in your hands when carrying it around, it has to feel just as natural and painless as carrying a paper notebook around.
The problem is that in the quest for small size and ultimate lightness, a number of sacrifices are made. Performance, keyboard, screen size/resolution, expansion, durability, battery life and price are all areas that you have to make sacrifices in if you want an ultra portable notebook.
You give up performance because the cooling and power requirements of a high speed CPU just aren’t possible to satisfy given the form factor and weight requirements of an ultra portable. There’s no budget for a large battery and heatsinks need to be on the order of millimeters in thickness. Ultra Low Voltage CPUs are generally preferred here and it’s only recently that we’ve seen ultra portables really get faster than 1GHz.
The screen size of a notebook actually determines the keyboard layout and size. In order to keep power consumption down, smaller screens with cramped resolutions are the norm in the ultra portable space. With a smaller screen, the keyboard that the screen covers when closed is similarly tiny. These two limitations generally run in contrary to one of the main uses for having an ultra portable: writing a lot becomes difficult. I owned a Sony X505 imported from Japan and it got me through my last year of college, but the keyboard was terrible to type on. It had a Japanese key layout so some of the key labels were in the “wrong” places. I had to rely on memory of a US keyboard layout to figure out which one to hit which is more difficult than you’d think on a keyboard with very small keys. Writing normal sentences wasn’t a problem, it’s the punctuation that really threw me off. My hands always had to do this strange ballet/gymnastics move in order to punctuate anything, which eventually drove me away from the notebook.
Expansion is an obvious problem; most of the ultra portables I’ve owned over the years didn’t have integrated optical drives, which made installing applications or just reading a disc handed to me while on the road frustratingly impossible.
In order to keep things light, ultra portables generally have tiny batteries and are built out of very lightweight materials - resulting in poor battery life and a hardly durable feel. The durability issue is compounded by the notebooks being very thin, which only makes them feel more likely to break. Admittedly I’ve never had an ultra portable break on me, but I’ve also never really dropped one. They do develop creaks over time just like other notebooks, there’s just no getting around that.
And finally we have the issue of price; the culmination of all of these sacrifices is a very light weight, very portable device...that also costs a great deal of money. Spending $2K - $3K on an ultra portable isn’t out of the ordinary.
Many consider Apple to be a leader in the computing world, but in many ways it is an attentive follower. Apple hasn’t historically been the first to introduce a new type of device, but rather a company that looks at where others have done poorly and attempts to do better. Apple didn’t invent the ultra portable, but with the MacBook Air it’s attempting to do it right.
With that pesky DTR out of the way, let’s get to know the Air a bit better.
The Air on Paper
On paper, the MacBook Air's size is impressive until you compare it to the MacBook - in many ways the Air is just a thinner MacBook. The screen is identical and the footprint is virtually unchanged. The two pounds Apple has managed to shave off and the reduction in thickness are huge, regardless of how small they may seem in numerical form.
|MacBook Air||MacBook||MacBook Pro 15"|
|Weight||3.0 lbs||5.0 lbs||5.4 lbs|
|Screen Size/Resolution||13.3" / 1280 x 800||13.3" / 1280 x 800||15.4" / 1440 x 900|
|CPU||Intel Core 2 Duo 1.6 - 1.8GHz (65nm Merom)||Intel Core 2 Duo 2.0 - 2.2GHz (65nm Merom)||Intel Core 2 Duo 2.2GHz - 2.6GHz (65nm Merom)|
|GPU||Intel GMA X3100 (144MB UMA)||Intel GMA X3100
|NVIDIA GeForce 8600M GT (128MB - 256MB)|
|Memory||2GB DDR2-667 (fixed)||1GB - 4GB DDR2-667||2GB - 4GB DDR2-667|
|HDD||80GB 1.8" HDD
or 64GB 1.8" SSD
|80 - 160GB 2.5" 5400RPM SATA HDD||120 - 250GB 2.5" 5400RPM SATA
200GB 7200RPM SATA
|Optical Drive||Optional External USB SuperDrive||Integrated Combo drive or SuperDrive||Integrated SuperDrive|
|Built in iSight||Yes||Yes||Yes|
|Inputs||1 x USB 2.0
1 x Integrated mic
|2 x USB 2.0
1 x FireWire 400
1 x Audio in
1 x Integrated mic
|2 x USB 2.0
1 x FireWire 400
1 x FireWire 800
1 x ExpressCard/34
1 x Audio in
1 x Integrated mic
|Outputs||1 x Audio
1 x Micro-DVI
|1 x Audio
1 x mini-DVI
|1 x Audio
1 x dual-link DVI
It Feels So Good
Apple can't help but talk up the fact that the MacBook Air is incredibly thin; something you honestly can't really appreciate until seeing/holding it in person.
The design is amazing and Apple's designers styled the Air in such a way that the shape of the notebook further accentuates how thin it is. It truly is beautiful, and I was a skeptic going into this review. PC notebook manufacturers are always asking me how they can better compete with Apple, designs like the Air are the perfect example of what we should be seeing from the Dells and Lenovos of the world but just aren't.
From top to bottom: iPhone, Macbook Air and the original MacBook Pro
The thinness is only a part of the equation however, unlike most ultra portables I've used over the years - the MacBook Air feels solid. Largely due to its aluminum shell, the Air feels unbelievably rigid - something I can't say about most ultra portables.
The screen hinge is also very tight but I'm unsure how that will wear over time; even the best constructed notebooks tend to fare poorly in this department as you use them.
The aluminum exterior does scratch pretty easily, even when taking good care of it we still managed to incur a few scratches on its underside. But just like dings on a new car, you get used to them after a while and stop worrying so much. The all aluminum exterior also means that it'll always shock me after going through airport security, just like my MacBook Pro - great; it's a small price to pay for a sturdy system.
The feet on the bottom of the Air are also very well done; they keep the system elevated enough to avoid scratching the base while flowing with the design.
The form factor of the MacBook Air is absolutely perfect, I can't stress enough how much Apple's entire lineup of notebooks needs to feel like the Air does in your hands.
Apple does fall very short in bundling accessories with the Air. At $1799 I don't expect Apple to include everything, but the Air really needs a well designed case. Apple kept mentioning that you can fit the Air inside a manilla folder, but failed to design a better alternative for you to stick it in when carrying it around. If you want to even attempt to carry accessories with the Air, you'll need a standard notebook bag which is designed for much larger systems - partially defeating the purpose of having such a thin and light notebook.
While I'd like to see Apple step to the plate and offer a case worthy of the Air, there is a great opportunity for a clever third party manufacturer to make something efficient for carrying the Air and its accessories around.
The Best Keyboard on an Ultra Portable? Evar?
I can't believe I'm typing this on an ultra portable. I covered CES on an ASUS U1E, which is considerably smaller than the MacBook Air. As pleasant as it was to use and type on, I still found myself running to my MacBook Pro whenever I really wanted to get some writing done. I needed the U1E's portability on the show floor but I needed the MacBook Pro's keyboard when I wanted to get work done. Apple's decision to include a full sized MacBook keyboard on the Air was perfect.
The keyboard is incredible. There's no searching for keys, no fat fingering any two keys and honestly the only complaint I have is that there are no dedicated page up/page down keys.
Typing on this thing is absolutely perfect, the keys have great tactile feedback and make a pronounced but pleasant sound when pressed. It's the same keyboard that's in the MacBook but I've never owned a MacBook, so I'm allowed to fawn on this one a little more than normal.
The edge of the Air's chassis is a little too sharp, which can make typing at some angles uncomfortable. I noticed it when I was using the Air but it wasn't a big enough deal to really bother me.
The fiber optic backlight on the keyboard is an absolute necessity; I'm shocked that more notebook manufacturers haven't adopted it by now. I'm writing this very paragraph in the dark with a well illuminated keyboard and it's great. The backlight alone isn't reason enough to recommend the MacBook Air, but it's a little feature that makes the ownership experience all that much more pleasant.
The keyboard backlight appears to stay on more aggressively than it should, at least compared to the MacBook Pro. The light sensors on the MacBook Pro are located under the speaker grills to the left and right of the keyboard, facing the ceiling. On the MacBook Air, the light sensor is located to the left of the iSight camera on the screen - perpendicular to the ceiling (and presumably the brightest source of light). The end result is the screen dims and keyboard lights up more aggressively than on the MacBook Pro. It's nothing terrible, just an interesting difference. I actually prefer the more aggressive keyboard backlight as a result.
The light sensor on the MacBook Air - to the left of the integrated iSight
There is a problem with the location of the light sensor however; since it's facing you and not facing up, if you are casting a shadow on the sensor it'll make the screen dim. That in itself is fine because you'll also be casting a shadow on the screen, but if you keep moving left and right - casting and removing your shadow from the sensor the LCD will get brighter and dimmer accordingly. If you keep in mind the position of the sensor it's not a problem, but if you don't realize where it is you may end up wondering why the screen keeps changing its brightness while the ambient lighting hasn't changed.
The eject button is kind of cute on the keyboard, when you press it you get the standard eject overlay on the screen - but obviously nothing happens. With the external SuperDrive attached, the button will eject whatever you put in the drive.
The trackpad on the MacBook Air is about the size of my iPhone. I've never really wanted a huge trackpad but there's nothing particularly wrong about it.
The nice thing about the MacBook Air's trackpad is that it'll keep working even if one of your hands is on it while you're using it. For example, if you're navigating around with your right hand while your left hand rests on the keyboard but some of your left hand happens to also rest on the trackpad, it won't confuse the trackpad - your mousing will continue uninterrupted.
Note that the trackpad attempts to differentiate between when you have part of your hand resting on it or a second finger on it. If it detects an extra finger-like point of contact it will assume that you have a second finger on the trackpad and change its function accordingly. However, if the trackpad detects a larger contact area with its surface it will assume that part of your other hand is simply resting on the trackpad and business will be as usual.
I was originally very skeptical of the multi-touch trackpad on the Air. It sounded far too much like an iPhone gimmick and didn't work nearly as well on the Air as it did on the iPhone. For example, if you make the pinch/stretch gesture with two fingers on the iPhone you will actually enlarge a portion of a web page in Safari. Doing the same on the MacBook Air adjusts the font size in Safari. In Finder, the pinch/stretch gesture changes the size of the icons but there's no easy way to go back to the default; at least in Safari you can hit Cmd + 0 to reset the font size.
That being said, the pinch/stretch gesture is my least favorite out of the bunch. The rest actually work surprisingly well.
The version of OS X that ships with the Air actually has videos built into the Trackpad Preferences Pane showing you how to use these gestures, as well as select which ones you want enabled or disabled.
Apple still only ships the MacBook Air with a single mouse button, so if you'd like a contextual (right) click you can either Control + Click or enable the mouse gesture: place two fingers on the track pad and then click the button.
If you want to rotate an image or a PDF simply place two fingers on the trackpad and rotate them around a fixed center point (much like turning an imaginary dial). The gesture works well but is best suited for image rotation. If you rotate an image using the gesture the animation is smooth and well done. Rotating a PDF document however is more rough and you generally only get a few frames of animation during the process, making it a little too distracting.
The best implemented gesture is the "Swipe to Navigate" feature of the MacBook Air's trackpad. If you'd like to move forward or back through web pages or folders in a Finder window, just place three fingers on the trackpad and swipe left or right. It's fast, it works and it's pretty useful.
What we're looking at with the MacBook Air's trackpad is the first implementation of multi-touch in a Mac. The hardware is mature enough today to implement what we've seen in the iPhone on a Mac, it's just a matter of re-architecting the OS around it. I suspect that by the time 10.6 rolls around we may be living in a more touch-friendly world.
So Bright, So Screen
The MacBook Air ships with a 13" 1280 x 800 LED backlit LCD panel. It's the LED backlight that allows Apple to keep power consumption low while driving a bright screen and keeping the form factor slim.
The original CCFL backlit MacBook Pro (back) vs. the LED backlit MacBook Air (front)
A more dramatic shot, the original MBP screen only looks this dark because it's placed next to the LED backlit MBA screen
The screen is absolutely amazing, it's so bright and crisp. At its highest brightness settings, the Air's screen is too bright for my eyes indoors. The glossy screen does exhibit some glare, which works well indoors but can be a pain outdoors.
The default OS X font and icon size actually works almost perfectly on the Air's display, any smaller and you'd get more people complaining about eye strain and legibility but Apple struck a good balance. I normally prefer a higher resolution display, but I was pleasantly surprised when using the Air. The screen resolution isn't nearly as big of a problem as I expected and here's where the OS X aspect of the MacBook Air really comes into play.
Window management has always been a strength of OS X, and Leopard makes things even better thanks to its built in support for virtual desktops with Spaces. Even on a single desktop, window presentation and access isn't really a problem on the 1280 x 800 display thanks to features like Exposé and Dashboard that help access occluded windows and keep clutter off of your screen.
A Sound Sleeper
I didn't really have a better place to talk about this in the review, but the way OS X handles its lid-closed sleep state is quite elegant. The OS will put the machine into a suspend-to-RAM state as well as copy the contents of its memory to the hard disk. Should you open the lid, you get the instantaneous wake of STR, and if you run out of battery you get the security of suspend to disk.
I ran out of battery power when the Air was asleep, I was greeted with this screen as soon as I gave the system power
Moving parts are always scary on computers. They are always built out of extremely cheap feeling, lightweight plastics and nearly always break off. Front doors on cases and nearly anything on a laptop falls into this category. Apple didn't have room to put any expansion ports on the MacBook Air so it used a flap that flips down revealing the Air's 3 I/O ports. Unlike most hinged items on a computer however the Air's expansion flap feels unbelievably secure; like most of the notebook it's built extremely well.
Unfortunately there are only three things on this flap: a headphone jack, a single USB 2.0 port and a micro-DVI port (Apple supplies DVI and VGA dongles with the Air for this port).
Apple had to ensure that the ports could remain extended while the system sat on a desk, so there were even more compromises made. Thicker USB devices including most 3G modems won't fit in the port, you'll need to rely on a USB extension cable for full compatibility (note that Apple doesn't make or ship one with the Air). The headphone jack is similarly finicky, if you had to buy a headphone extension dongle for your iPhone you may need it on the MacBook Air as well.
The single USB port is a bit bothersome especially when you think about all of the additional functionality you may need to add to the Air given its stripped down status.
Designed for a Utopian Society
There is no Ethernet port on the MacBook Air, your only built in connection to the outside world is the 802.11 b/g/n Wi-Fi that ships with the system. There's also no built in support for cellular 3G networks, which is a bit surprising given Apple's close relationship to AT&T courtesy of the iPhone.
I'm not too blown away by the lack of an Ethernet port coming from my previous ultra portables and I understand the reason for not including one - it's purely an aesthetic choice. Many have faulted Apple for its form over function approach to the MacBook Air, but the fact of the matter is that the Air has garnered more mainstream attention than any other ultra portable I've seen. Part of that is the Apple name, but a lot of it has to do with the styling of the machine.
Apple offers a USB Ethernet controller for $30 that works fine with the Air and will give you full 10/100 Ethernet speeds.
We ran a few benchmarks as a sanity check to make sure you wouldn't be sacrificing any performance by using Ethernet over USB:
The results were as expected, Apple's USB Ethernet dongle is just as good as an integrated solution. The only real complaint we have is that you have to pay an extra $30 for the privilege to have Ethernet on your Air.
For an extra $100 Apple will sell you a SuperDrive for the MacBook Air.
It's incredibly thin and powered completely off of the MacBook Air.
The drive works fine, just plug it in and go. Carrying it around alongside your Air does sort of defeat the purpose of the ultra portable. I guess it's ok if you can stick it away in your luggage somewhere.
Installing Mac OS X
With no built in optical drive you have to rely on the network for all CD/DVD based application and OS installs, or spend the $100 on an external drive.
With the version of OS X that ships on the MacBook Air, Apple has enabled the first unbelievably seamless network boot function I've used on a computer. Just hold down the option key when starting up and you'll get a drop down of available wireless networks. Select the one you want to join and any shared OS X discs will appear in your boot menu above.
In order to share an OS X disc for installation you need to install some software on your Mac or PC. The Remote OS X Installation software allows your Air to see and boot from a OS X install disc over the network - you can choose whether wireless or wired if you have the Air's Ethernet dongle.
Installing OS X on the MacBook Air already takes around two hours thanks to the incredibly slow disk drive, but it's even longer if you do it remotely. Over 802.11n it took around 2.5 hours for a complete install of Leopard.
Application installs work similarly; just install the remote disc software on the machine whose optical drive you're going to be leeching and the Air will handle the rest. Obviously encrypted content won't work remotely, so no store-bought DVDs will play over the network. Thankfully most OS X applications can install by simply copying over the .app container, making a network install pretty easy.
Getting video on the Air all but requires you have unencrypted content so, um, XviD rips for all. It's almost as if Apple is encouraging piracy by not including an external optical drive with the MacBook Air. Be warned however, the argument that Apple made you download a rip of Superbad probably won't hold up in your court case against the MPAA.
The remote disc stuff works fine but it's not so useful if you're on the road, which means the $100 external optical drive is probably a good investment. I've owned enough ultra portables without integrated optical drives to know that even when you think you hardly use one, you'll be frustrated by all the times you need one but don't have it.
Inside the Air
The MacBook Air uses a 65nm Merom based mobile Core 2 Duo CPU running at 1.6GHz. For an extra $300 you can upgrade the chip to a 1.8GHz part (note that Intel only charges Apple an extra $32 for the faster CPU). Despite the high markup we do recommend the faster CPU since its soldered onto the motherboard and you can’t upgrade it yourself after the fact.
The CPU used in the MacBook Air isn’t your run of the mill mobile Core 2, instead it uses a new small form factor packaging that Intel was originally going to debut at the end of this year. It seems as though Apple (and maybe other partners) put enough pressure on Intel to introduce the SFF chip/chipset packaging earlier than expected, enabling designs like the Air.
The CPU and chipset die aren’t any smaller, but the package that the die sits on is reduced by approximately 60%, enabling a smaller motherboard footprint.
The CPU runs at a lower voltage than stock mobile Core 2 processors, but at a higher voltage than the LV (Low Voltage) Core 2s. We hypothesized that the reason for a higher voltage than a LV chip was because of the more exotic packaging, requiring a higher core voltage to ensure proper power delivery to the chip.
The motherboard is quite compact, looking more like a board from a large smartphone rather than something you'd find in a Laptop. Most of that is because there is no expansion on the board, everything is soldered on.
In order to limit motherboard footprint and power consumption, Apple stuck with Intel's GMA X3100 integrated graphics on the Air. The GMA X3100 is by no means a bad solution, especially if driver support is good (Apple does much of the driver development for OS X so it's difficult to compare) but it's far from fast. Luckily this is one of those situations where OS X not being a gaming platform works in Apple's favor.
The X3100 is fast enough for most OS-level operations, although functions like Exposé are choppier than on discrete graphics thanks to the lack of any local video memory (video memory is carved out of system memory).
Coverflow's animations work as smoothly as they do on the Mac desktops, it's mainly the memory intensive video operations that can get sluggish on the X3100. That being said, you need to have around 25 windows open before full screen Exposé really gets distractingly choppy.
Professional applications that have discrete graphics requirements obviously won't work on the GMA X3100, but we don't expect the Air to really be used as a professional workstation.
Video out on the MacBook Air is limited to 1920 x 1200 since it's only got a single-link DVI output. Enabling an external display is really simple - just plug it in and everything works.
Little or No Upgrade Path
Allow me to make this very clear: the useful lifespan of the MacBook Air is very limited. Because you're mostly paying for the portability of the notebook, the Air isn't blessed with particularly speedy internals. Thankfully Apple outfitted it with a reasonably clocked Core 2 Duo, but in a year's time 1.8GHz won't really be all that impressive. We'll be seeing mobile Nehalem, which will continue to improve performance while dropping power consumption. While I don't expect the clock speeds to increase that much at the same TDP (Apple might be able to get a 2.0GHz chip in here), the performance and battery life changes will be noticeable.
The CPU in the Air is soldered on to the motherboard, so there's no replacing it. Even worse, the memory is also soldered on the board and there are no expansion slots. So you're stuck with 2GB of memory from now until the day you buy a new notebook. The only component you can really upgrade is the hard drive, which helps this from being completely depressing but isn't enough.
The CPU and half of the Air's memory are visible here, all soldered onto the motherboard
Obviously you can continue to use the MacBook Air as long as you'd like, but be aware of its planned obsolescence. The lack of memory slots is quite possibly the biggest issue, especially as applications grow in size. I remember reviewing the first Mac mini and complaining about not having 512MB of memory standard; these days 2GB is my sweet spot for OS X, and luckily Apple has outfitted the Air with just that. It'll be another year or two before 4GB is the minimum smooth requirement for a decent OS X machine, but when that rolls around you're out of luck with the Air.
Don't buy this notebook if you're not comfortable with having to buy a new one in another year or two. For the target market with the sort of disposable income necessary for such a habit, it's not a terrible commitment.
An iPod Hard Drive in a Mac?
One of many sacrifices made in the quest for the thinnest notebook in the world in the hard drive department. The MacBook Air ships with an 80GB 1.8”, 5mm thick, 4200RPM PATA hard drive while most regular notebooks feature much faster 2.5” drives with larger platters that spin at 5400 or even 7200RPM. Apple does offer a supposedly faster 1.8” solid state drive (SSD) as a $999 option, but given the price most will opt for the standard HDD.
From left to right: 1.8" Air HDD, 2.5" standard notebook HDD, 3.5" standard desktop HDD
The 1.8" HDD’s performance limitations are visible from the start. Spotlight searches aren't always instantaneous but on a brand new machine they tend to be faster than they were on the Air. OS X does a great job of hiding slow disk performance (subjectively much better than Vista, but I don't have scientific test results to back that up), but even then the drive is a clear limitation of the system.
For basic typing, email and web surfing it's fine. If you throw in some multitasking, spotlight searches and start launching some more complex applications, then you really see the drive choke. We wanted to see if the SSD would fix these issues, so we set out on upgrading the drive in our MacBook Air.
Hard Drive Swap: DIY SSD Install
Samsung is the sole supplier for both the solid state and mechanical hard drives in the MacBook Air. The mechanical drive is a Spinpoint N2 HS082HB/A while the SSD is the MCCOE64GEMPP.
DVNation offers the Samsung SSD for sale on its website and was kind enough to send us a drive so we could swap it into our MacBook Air. The drive swap process is pretty simple, first you have to remove the 10 screws that secure the base of the Air:
You'll want to keep track of where you pulled the screws out of, they are varying sizes
After removing the bottom panel you need to remove the battery:
With the battery removed you need to then remove the speaker, which is housed in the long black bar next to the battery:
Two screws hold the speaker in place
After the speaker is out you need to unscrew the flip-down ports on the Air (you should also disconnect the ribbon cable attached to the ports from the motherboard to make things easier):
Disconnect this cable from the motherboard
Then flip the ports out of the way
Now we can get to removing the hard drive itself. The hard drive is put inside a rubber frame and inserted into a plastic bracket, the bracket is then screwed into the Air's chassis. The bracket is held in by four screws, one of which is hidden by a removable cable guide:
Unscrew all four screws, disconnect the hard drive from the motherboard and you should be able to tilt the bracket out and away from the Air enough that you can just pop the drive out.
Unplug the HDD from the motherboard, just pull straight up on the connector to free it.
With the drive removed take off the rubber frame and stick it on your new drive.
There's a piece of black tape that helps hold the ZIF connector in place, peel it off; you'll probably need a replacement piece of tape as the one that ships with the Air is only good the first time, once you've removed it much of the adhesive is already gone.
With the tape off just pull the cable out of the old drive and stick it in the new one.
We found that the connector on the Samsung HDD Apple used had a more snug fit than the SSD we received from DVNation, we're not sure if this is a modification Samsung made for Apple and if it's possible to get a drive after market with the same drive-end connector. Having a snug fit is very important as we found that unless we taped the cable in place very well, the drive would sometimes not be detected by OS X upon boot. Make sure the connector is secure and then reverse the process to install the new drive.
The mechanical HDD does have some cushioning glued to it, while this isn't totally necessary on the SSD (as it has no moving parts) it wouldn't hurt to move over to the new drive if you can manage to peel most of it off. For the purposes of this article we didn't attempt to move the padding over to the SSD.
With the SSD installed, it was time to benchmark it.
MacBook Air Performance: SSD vs. Mechanical HDD
We took the same MacBook Air and just swapped drives for running these tests, you can't get more scientific methody than that. First up are some synthetic tests to help set expectations, for that we turned to XBench 1.3.
XBench isn't a particularly good benchmark for OS X, but it does have a basic drive performance test that suits our needs:
|XBench 1.3 256KB block Disk Tests||80GB 4200RPM HDD||64GB SSD|
|Sequential - Uncached Writes||28.4MB/s||24.6MB/s|
|Sequential - Uncached Reads||28.0MB/s||49.9MB/s|
|Random - Uncached Writes||20.6MB/s||17.8MB/s|
|Random - Uncached Reads||13.0MB/s||49.2MB/s|
The trends are pretty clear here: write speed is about 17% faster on the mechanical HDD while read speeds are much higher on the SSD, particularly when they aren't sequential reads. Since the mechanical drive has to worry about locating data on a spinning platter, random data spread out over the relatively slow spinning platter takes time to access. The SSD benefits from having an equal access latency to data regardless of where it's located in the drive's flash memory.
While most desktop applications are quite sequential in nature, multitasking can change I/O access patterns considerably.
Our first set of real world tests on the SSD are basic stopwatch application launch tests. We took 7 applications and timed how long they take to start up on the mechanical drive vs. the SSD:
|Application Launch Time Tests||80GB 4200RPM HDD||64GB SSD|
|Adobe Photoshop CS3||18.0s||6.9s|
|iWork '08 - Pages||11.0s||3.5s|
|iWork '08 - Keynote||13.0s||6.3s|
|iWork '08 - Numbers||7.1s||3.5s|
|Microsoft Word 2008||28.8s||11.0s|
|System Boot Time||54.4s||32.5s|
The SSD completely destroys the mechanical disk in application launch times, and these results aren't just numerical, they are very noticeable in using the system. The SSD is noticeably faster in application launches, accessing files in Finder and spotlight searches. After I used the SSD MacBook Air, I tossed the standard HDD back in and honestly thought something was wrong - it felt significantly slower, despite feeling mostly "fine" before I was exposed to the SSD.
Most application level benchmarks however favor the higher write speeds of the mechanical disk instead:
|Application Benchmarks||80GB 4200RPM HDD||64GB SSD|
|Word 2008 - Compare Docs||107.8s||109.3s|
|PowerPoint 2008 + Word, Print PDF||149.0s||162.6s|
|Quicktime H.264 Encode||5.6m||5.8m|
Most of these benchmarks show the SSD as slightly slower than the standard HDD, but a couple are noticeably faster on the standard drive thanks to its write speed advantage. The SSD recommendation would be an easier one if the benchmarks clearly leaned in one direction or another, but it's not as difficult as you might think on first glance.
The split between reads and writes on a desktop system is biased towards read performance, so you're more likely to notice the SSD's faster read speeds than its slower write speeds. The theory was echoed in my real world usage of the machine, the SSD was just faster.
The Impact of SSD on Battery Life
One advantage of solid state storage is lower power consumption thanks to not having any motors or moving heads to drive; spinning anything 4200 times a minute is going to be more power hungry than a solid state solution. The SSD vs. mechanical HDD power debate would normally be a clear cut one but we're comparing to one of the lowest power HDDs on the market here.
|Power Consumption||80GB 4200RPM HDD||64GB SSD|
The power savings are dramatic; idle power is reduced by nearly a factor of 10, standby power is cut in half and read/write power is at worst a third of the mechanical drive. The 10x idle power reduction is important since that's where your drive should be spending most of its time, and if the average power savings is somewhere in the 0.25 - 0.5W range you're looking at improving battery life on the order of tens of minutes.
To find out the impact on battery life we ran through three different scenarios:
I scripted together three tests: wireless web browsing, DVD playback and a multitasking workload.
The wireless web browsing test uses the 802.11n connection to browse a series of 20 web pages varying in size, spending 20 seconds on each page (I timed how long it takes me to read a page on Digg and came up with 36 seconds; I standardized on 20 seconds for the test to make things a little more stressful). The test continues to loop all while playing MP3s in iTunes. This test is designed to simulate the intended usage of the MacBook Air: something you can carry around with you to class, work, on the train, etc... to comfortably and quickly browse the web, take notes and generally be productive all while listening to music. It's like a big iPhone...without the phone part.
Despite the lack of an internal optical drive (I've never been so tempted to use the f-bomb in a review before), the MacBook Air will play DVDs. You just kind of need to have them on your hard drive and I'll just assume you have the original disc safe at home. This test is simple: I play Blood Diamond in a loop until the battery runs out.
The final test is the multitasking workload, and this test isn't really that intensive for a normal system but thanks to the terribly slow iPod hard drive in the Air - it's quite stressful. For this benchmark I'm downloading 10GB worth of files from the net (constant writes to the drive), browsing the web (same test as the first one) and watching the first two episodes of Firefly encoded in a 480p XviD format (Quicktime is set to loop the content until the system dies). There's nothing too extreme about this workload, I could definitely come up with worse - but this would be light to moderate usage on a MacBook or a MacBook Pro, and it'll show how the Air stacks up.
The system was set to never shut off the display and never go to sleep, although the hard drive was allowed to spin down when possible. The display brightness was set at 9 blocks (just over 50%), which I felt was comfortable for both day and night viewing.
|Battery Life Test (H:MM)||80GB 4200RPM HDD||64GB SSD||% Improvement|
|Wireless Internet + MP3||4:16||4:59||16.8%|
|Heavy Downloading + XviD + Web Browsing||2:26||2:42||11.0%|
As expected, the impact on battery life isn't huge but it's definitely noticeable. With the 64GB SSD installed we're actually able to hit Apple's 5 hour battery life claim with the MacBook Air. Our wireless browsing test actually saw the biggest improvement in battery life, increasing a full 43 minutes from a simple drive swap.
The DVD playback test got the next largest boost of 31 minutes or 15.1%, followed by the multitasking scenario that saw a more meager 16 minute increase in battery life.
With an average increase in battery life of 30 minutes, you're paying an extra $33 per minute of battery life based on present day SSD upgrade pricing from Apple. If you look at it that way, the improvements stop being as exciting - but the takeaway point is that the technology is useful and down the road, when SSD prices drop, you can look forward to an upgrade that does improve the overall experience.
The SSD Discussion
Apple inadvertently mitigated some of the dangers and annoyances of a mechanical hard disk in the Air by going with a 1.8" drive. These drives are used in the iPod and are designed to be rugged, cool and quiet. Because we're comparing an already low power, quiet drive to the SSD many of the advantages of the SSD just aren't as noticeable.
One aspect of SSD performance that isn't often talked about is that performance doesn't change as the drive gets fuller. Mechanical disk drives are designed to write to the outer most sectors first (where read speed is the fastest) and the inner most sectors last (where read speed is the slowest). When your drive is mostly empty, everything gets written to the fast part of the disk. As it gets full, data is written to the slower parts and thus you get degraded performance. The same doesn't apply to a SSD, since we're just writing to flash; performance is the same regardless of what part of the flash you're reading from.
If money were no object and we had to make a recommendation today, we'd still take the SSD over the mechanical drive. It is more responsive in the areas that bothered us the most when using the Air, it increases battery life by a good 14% on average and most importantly - it lowers the risk of a drive failure while on the road. The first stipulation of that recommendation is the one that's worth paying attention to: if money were no object.
Apple charges a hefty $999 for the 64GB SSD option, and on a $1799 notebook that's not insignificant; we're talking 55% of the price of a standard MacBook Air just for a drive swap. Apple isn't making that much profit on the drive either. The 64GB Samsung SSD Apple uses in the Air costs around $760, Apple actually makes more from the 200MHz CPU upgrade than the $999 SSD.
The beauty of solid state storage is that it's based on Flash, whose prices are directly influenced by Moore's Law. We've been told that within 3 months you can expect the cost of these 64GB SSDs to drop by around 30%, so we'd be looking at around $530 for the same drive in the near term. Obviously we're talking about cost here, if we apply the same 28% markup Apple currently uses on the SSD option to the new price we get around $680 for the SSD upgrade in 3 months. There's no guarantee that Apple will pass on the savings but if they don't, you can always shop around for the drive from another vendor such as DVNation.
Price isn't the only thing that will improve with time: performance will as well. When the transition to solid state disks first started happening the controllers (the chip that sits between the PATA/SATA interface and the Flash memory) were hardly optimized for performance. Because performance was so poor, the first SSDs were used for industrial applications where the ruggedness of the drives were most important and performance didn't really matter.
As controller technology advanced, so did performance but since the SSD market was still small the manufacturers had to pick and choose their battles. The natural fit for higher performance drives was the 2.5" SATA SSD market, after all these drives would be going into expensive notebooks. Controller development for PATA drives just wasn't as far along and thus PATA SSD offerings generally lagged behind in performance compared to their SATA counterparts.
The ZIF connector, it's bendy
In order to maintain the slim form factor of the Air, Apple stuck with a PATA interface for the hard drive; this isn't your grandmother's 44-pin PATA connector, it's a 40-pin low profile, ZIF (Zero Insertion Force) ribbon connector. There is no SATA equivalent so if you want to build a very small device you need to rely on a PATA drive, which is exactly what Apple did. Unfortunately, it also means that the $999 SSD Apple uses isn't the fastest SSD in the world - the 2.5" models are much quicker.
What about Smaller SSDs?
While the 64GB drive used in the Air is fairly expensive today, you can find cheaper 32GB drives on the market. The cost to manufacture the 32GB version is exactly 50% so the retail price ends up being about half as well. The problem is that 32GB isn't enough space for an often used OS X machine.
The default install of OS X and all of its applications that ship with the Air eats up close to 20GB of space; add a few necessities like Microsoft Office or Photoshop, not to mention copying DVDs/movies to your hard drive to watch them unless you want to lug around the external DVD drive as well and you'll quickly run out of space on a 32GB drive.
Ouch, only 19.96GB free? Hurry up Moore, we need larger SSDs.
When we were done installing all of the applications and test files needed for our benchmarks on the 64GB SSD we only had 19.96GB available. That's more than enough if you never install another application or copy any large content over, but chances are that won't happen.
Your best bet is honestly sticking with the 80GB PATA drive (unless money really isn't an object in which case just buy the SSD now and buy a larger one later) and upgrading to a 64GB or larger SSD when they are available.
Overall System Performance
The next question is: how much performance are you giving up for portability with the MacBook Air? We compared the Air to two other Apple notebooks: the original MacBook Pro based on a Core Duo (not Core 2) running at 2.0GHz and the latest MacBook Pro with a 7200RPM HDD and 2.6GHz Core 2 Duo. All systems were configured with 2GB of DDR2-667 memory.
We ran two iPhoto tests, one of which we've used in the past several Apple reviews. We simply time the import of 379 images into an empty iPhoto album. This test is both processor and disk intensive, which should be fun on the slow HDD in the Air:
The fastest MacBook Pro is nearly twice as fast as the MacBook Air, the standings aren't unexpected but the margin of victory is a little surprising. The more interesting comparison however is between the Air and the original MacBook Pro - the two perform identically.
Our next test takes the pictures we just imported and exports them to a multi-page website, once again we're measuring completion time in seconds:
Here the MacBook Air is actually faster than the old MacBook Pro. The new Pro is still significantly faster.
iWork '08 Performance
What do iWork users often find themselves doing? Exporting their wonderful documents to formats that can be used by Microsoft Office users. Thus our Pages and Keynote benchmarks involve exporting to Word and PowerPoint respectively:
Both benchmarks continue the trend we've seen: the ultra-fast MacBook Pro is faster, while the Air actually outperforms the original MBP released two years ago.
Microsoft Office 2008 Performance
Our Word 2008 test comes from Intel and times how long it takes to compare two different versions of the Count of Monte Christo using Word's built in document compare function:
The 2.6GHz MacBook Pro is a good 40% faster than the Air (I'd expect the 2.2GHz model to have a 25 - 30% advantage), while both versions of the Air are a good 20% faster than Apple's first Intel based notebook.
Our multitasking Office 2008 is another Intel-supplied benchmark; this one has us running the document compare test from above, while printing a PowerPoint presentation to PDF. Note that the original MacBook Pro took so long to complete this test that we had to just give it a DNF score and leave it out of the chart:
File Decompression, Photoshop and Quicktime Performance
Using MacPAR Deluxe we took an 800MB archive and deleted 5% of it, forcing MacPAR to read the archive, calculate and write the missing bits, then extract the whole archive:
As we saw in our SSD performance pages, the SSD just can't keep up with the standard hard drive here making it slower than the old MacBook Pro. The fastest MacBook Pro is around 20% faster than the Air, which itself is faster than the old MBP.
Our CS3 benchmark is the standard Retouch Artists test that we use in our CPU reviews. We're just timing how long it takes to complete a handful of operations on an image in Photoshop:
While the MacBook Air can handle Photoshop as well as a two year old MacBook Pro, if you're serious about image editing you may want to deal with lugging around 2 more pounds and get the MacBook Pro.
Finally we have our Quicktime H.264 encode test. All we're doing here is taking a 500MB MPEG-2 avi file and encoding it using Apple's H.264 codec and Quicktime's default settings:
Quicktime agrees with the rest of our tests, now time to discuss what we've seen.
Quite possibly the most surprising results we saw in our tests were those that compared the MacBook Air to the original Core Duo based MacBook Pro. The MacBook Pro is two years old now and in that time, Apple has managed to offer the same if not better performance as the first MBP in the MacBook Air. Battery life of the first MacBook Pro is also equalled by the Air.
Comparing the top of the line MacBook Pro from 2 years ago to the highest end MacBook Pro today shows the other side of the Moore's Law coin: performance and battery life improves tremendously over time. While Apple can now cram the performance of the first MacBook Pro into the Air's chassis, it can also offer nearly twice the performance and battery life into the same size chassis as the original MBP. Obviously the improvements come from more than just a faster, more efficient CPU (LED backlight, newer hard drive tech, etc...), but the culmination is tremendous.
When looking at the MacBook Air as a 1 - 2 year purchase, the performance difference between a 2 year old MacBook Pro and a present day one is great enough that we'd almost say the somewhat disposable nature of the Air isn't such a big deal. So what if you have to toss it and buy a new one in 2 years? Chances are, you'll probably want to anyways thanks to the sort of performance gains you'll see.
A two year upgrade cycle also puts you in sync (byebyebye) with Intel's major CPU architecture refreshes, theoretically giving you major increases in performance and power each time you snag a new notebook. I honestly didn't realize how slow my MacBook Pro had become until I benchmarked the latest model, the performance/battery life figures speak for themselves.
It's also nice to wonder if the MacBook Air 2 years from now will offer performance similar to the 2.6GHz MacBook Pro we compared to today. With a much faster SSD and 45nm Nehalem based CPU, I think that may actually be a conservative estimate.
I've been using a MacBook Pro and a Mac Pro, both originals (that's Core Duo and Core 2 Duo based respectively) ever since their release. The Mac Pro gets regular usage while the MacBook Pro is more for trips or when it's really nice outside. Compared to both of these systems, the MacBook Air doesn't feel sluggish at all.
I opted for the 1.8GHz Core 2 Duo because of the lack of a CPU upgrade path, unlike my Mac Pro which gladly accepted 3.0GHz Xeons when I asked it nicely. For its intended purposes, the MacBook Air performs admirably - and as you'll see from the performance results, it actually does surprisingly well compared to the original MacBook Pro.
By far the most noticeable performance issue has to do with the mechanical disk drive. Spotlight searches, application launches and even boot time are all noticeably slower than I'd like and it's all thanks to that 1.8" 4200RPM HDD.
Sequential transfer speeds of large files isn't a problem, but random small file access (e.g. a Spotlight search) is hard on the drive. Simultaneous reads and writes will also make the disk choke, especially if they are moderately strenuous. Basic web browsing and downloading isn't a big deal, but add some file copies and reading of 10MP images and then you're looking at a frustrating time. The SSD fixes these issues for the most part because of its much improved random read/write performance, thanks to the lack of rotational latency.
Overall I'd say the MacBook Air is the perfect speed for its intended use, even taking into account the disk performance issues. Usually I'm left disappointed by the performance of the ultra portables I've used, but that's because they are generally relying on very low clock speed ULV processors to do all the work. Apple's use of a 1.6 - 1.8GHz Core 2 was the right decision in my opinion.
When Apple announced that the MacBook Air would have a 5 hour battery life I couldn't help but laugh. As Charlie over at the Inquirer pointed out, Apple did nothing new with the MacBook Air. The tough engineering was done by Intel and the component suppliers, Apple simply designed the chassis. Because Apple is doomed to use off the shelf components like everyone else, there's no magical way Apple can deliver 5 hours of battery life where its competitors have failed.
Close to 5 hours is attainable on the Air, but only in a very light usage scenario. Realistically you're looking at 2 - 4 hours of battery life out of the MacBook Air depending on what you're doing. In order to help set expectations, we've got a few battery life tests we put together (the descriptions of the tests were mentioned earlier on the SSD battery life page).
Apple's 5 hour claim is laughable but not as much as I expected. If I wanted to I suspect I could hit 5 hours by making the web browsing test less stressful, but my focus was on real world usage scenarios, not proving Apple correct. Regardless, 4 hours and 16 minutes doing what I consider to be the intended usage model of the Air is respectable. It's not great, but it's not terrible either.
The SSD improves things considerably, and it's worth noting that the fastest MacBook Pro can also offer similar battery life despite having a more power hungry CPU and screen (thanks to a larger 60WHr battery). The aging Core Duo based MacBook Pro put up an absolutely dismal time, which just goes to show you how much things can change in two years.
The DVD playback test is also decent, you can watch a full length movie on the Air (even The Godfather). But watching two back-to-back isn't possible (although I do think you could squeeze two viewings of Rambo in there and frighten your fellow airline passengers).
Once again we see that the Air gives us better battery life than the original MacBook Pro, and a time that's competitive with the fastest MacBook Pro. Armed with an SSD, the battery life is the best Apple offers today.
And then we have the multitasking scenario. At just under two and a half hours, this isn't your do-everything notebook. That should've been obvious from the get-go with the whole lack of an optical drive, 2GB memory limit and no built-in Ethernet port. The MacBook Pro advantage here is the greatest it has been in all of our tests, giving almost 30% more battery life than the standard Air.
My MacBook Pro got hot, unreasonably hot. So hot in fact that it couldn't really be used on my lap without me getting really sweaty or burnt after a while. The CPU in the MacBook Air is a 1.8GHz Core 2 Duo compared to the 2.0GHz Core Duo in my old MacBook Pro, however it is a lower voltage chip.
The lower voltage, lower clock speed, more power efficient architecture and the maturity of Intel's 65nm process all contribute to the Air having a reasonable thermal footprint.
During normal use the Air gets warm but not too uncomfortable to use on your lap. If you're doing more than just typing/browsing with it, the system can get too warm to use on your lap. It definitely got there for me a few times while putting together this article, but it may vary depending on your tolerance for heat on your lap (and your desire to become infertile).
It's still miles better than my old MacBook Pro and for the most part I can use it as a laptop, but it does still get borderline uncomfortable once the CPU heats up.
The hard drive itself doesn't generate a lot of heat, which is surprising given that it's got a platter spinning at 4200RPM inside of it.
Air comes in and out of there
The MacBook Air does have a single fan to cool the entire system and it's not difficult to hear when spun up. It never gets as loud as the fan in the MacBook Pro but you're aware that it's working.
Despite being a first generation Apple product, I didn't have too many really odd issues with the MacBook Air. After replacing the hard drive the drive would sometimes not be detected by OS X, but that ended up being an issue with the connector not being seated properly.
Excuse me, it's going to take how long?
The biggest issue I ran into was that while the system would normally only take around 3 hours for a full charge, on two separate occasions it took nearly 8 hours to charge. A number of users have complained about similar problems on Apple's support forums, but for me the problem disappeared after the two isolated incedents and hasn't returned since.
I started this review by defining the expectations of a notebook like the MacBook Air. The problem is that Apple's mainstream popularity has made a device like the MacBook Air, which would normally be targeted at a very small niche, appeal to a much wider audience. Most who are considering the MacBook Air would probably be sorely disappointed by it, because they want a smaller MacBook - not an ultra portable. Apple doesn't offer a smaller MacBook and thus I find myself writing a conclusion for a wide variety of people.
I'll start with the general populace and drill down to the intended audience of the MacBook Air, and how the notebook fares when presented to each type of user.
As a standard notebook, the MacBook Air falls short in the most obvious of ways. It's hardly expandable, it has no integrated optical drive and it's got a fairly small, low performing hard drive.
I've already talked to far too many people that are allowing emotion to cloud better judgment and are considering the Air when they shouldn't be. If this is going to be your only notebook and you plan on using it as your main computer, chances are the Air isn't for you. It does look very cool and it's incredibly light, but ultra portables are the exotic cars of the notebook world. If you own an exotic it's generally not your only car, you've got other things more practical in the stable so you don't end up driving a Ferrari in two feet of snow.
Part of the problem with the MacBook Air is that it's designed for a world that doesn't exist yet. Wi-Fi access just isn't ubiquitous, you need to rely on a combination of Ethernet, WiFi and a 3G modem if you really want connectivity. The portability of the Air starts to be challenged once you look at carrying around various dongles and such. Apple has a great relationship with AT&T right? Why not allow the iPhone to tether to the MacBook Air or at least let you stick your SIM card in it to enable a 3G modem. I expected more from Apple in this regard, which brings me to my next point.
Apple had the chance to really revolutionize the ultra portable world, but instead it provided its own sheep for the flock. It's not a bad notebook by any means, but Apple's constant praise in the media also means that it must be held to a higher standard of scrutiny. I'd be blown away by the Air if it were built by Dell or Gateway, but from Apple I expect more than a nice design.
The iPhone was the result of very clever engineering, it was a hardware and software solution to a problem that impacted many. The same could have been true for the MacBook Air; it could've revolutionized mobile computing and raised the bar for how thin and how light we expect our notebooks to be. The MacBook Air is an amazing chassis coupled accented by good hardware choices but with very little added innovation or engineering. You may think I'm being too harsh on Apple, but the fact of the matter is that I wanted the iPhone of ultra portables and got a thin MacBook instead.
Now if you're specifically looking for an ultra portable and are part of the willing to sacrifice/spend niche that the Air should be targeted at, then we need to be having a very different discussion.
Sure expansion is limited, the thing is expensive and at least two accessories should be included from Apple but aren't - but would you look at this thing?
The build quality of the Air truly stands out among all of the incredibly impractical notebooks I've used in the past - it's excellent. Generally you see an ultra portable and are impressed, then you hold an ultra portable and are scared. The same just isn't true with the MacBook Air; it feels just like it looks and it's surprisingly sturdy.
As the MacBook Air is the only ultra portable Mac around, in many senses it doesn't really have any competitor. Sony, Dell and more recently Lenovo all have similarly equipped notebooks but none of them run OS X. When I first reviewed OS X on a notebook I talked about how many of its strengths really came in handy in a cramped screen environment, which is what you get with a notebook. On an ultra portable machine like the MacBook Air, especially one with a fairly low screen resolution, the window management strengths of OS X grow even more important.
The full sized keyboard is a must for any writer and it's a decision that I'm beyond glad Apple went with on the Air. This entire review was written on the Air and it was done even faster than if I were at my desk typing it all out, mostly because I could be in whatever more comfortable environment I wanted to be in while writing it. If you need something ultra portable it's generally because you want to carry it around with you all the time and presumably use it for something. The CPU and keyboard choices Apple went with made it so that you can actually get work done on the MacBook Air.
Apple did sacrifice a lot with the Air, the lack of an optical drive and limited expansion both come to mind. But honestly, it's all made up for by the form factor, build quality, CPU speed and keyboard decisions. Apple may have given up a lot but these four factors have made it so that the MacBook Air will be my desired travel companion from now on.
That's just me however, if you're not a fan of OS X then the MacBook Air loses one of its biggest assets and you have to start looking at things a little differently. Had the Air been more revolutionary it would've been the ultra portable that pulled in Windows users, much like the iPhone reached out to more than just Mac users.
As it stands, if you're an OS X user the MacBook Air is a solid ultra portable. If you're a windows user with no interest in OS X, the Air just doesn't make sense - luckily you have many more ultra portables to choose from.
For Apple the iPhone changed everything, we must now grade both the hardware and Apple itself for the product. The MacBook Air gets the nod and although Apple gets a B for effort, we expect more. You've gotta earn that stock price Steve.