The Apple iPad 2 Review
by Brian Klug, Anand Lal Shimpi & Vivek Gowri on March 19, 2011 8:01 PM ESTBattery Life
Testing battery life on a tablet is pretty grueling as these things are effectively smartphones with gigantic batteries. What would last for only a few hours on a smartphone can easily last over ten on a tablet. The iPad 2 is no exception.
As iFixit discovered, the iPad 2 features a nearly identical battery to the original iPad (25Wh vs. 24.8Wh). We already established that display brightness hasn't gone up so the only real impact on battery life will be because of the A5 SoC.
The iPad 2 WiFi's battery, courtesy iFixit
The ARM Cortex A9 tends to be more power efficient than its predecessor, the A8. With a shallower pipeline and the ability to execute instructions out of program order you get better performance per watt in most cases. As a result the A5 should complete bursts of instructions quicker than the A4 and get back to sleep sooner.
To put this to the test we put together a battery life test that combined our non-Flash smartphone web browsing test, checking for email every 15 minutes (via a Gmail account receiving ~100 emails per day) and constant local music playback while all of this is going on. The results are pretty much as expected:
Over WiFi the Motorola Xoom and iPad 1 deliver very similar results. The iPad 2 pulls ahead by around 8%, it's not a huge advantage but it's there. Over 3G there's a noticeable drop in battery life, putting both of the iPad 2s below 10 hours and kicking the Xoom down to under 9 hours. All of the numbers on this chart are respectable however and you can expect a good day's worth of use out of any of these tablets.
Note that while the iPad 2 did better than its predecessor if you were to run an app that pegged both CPU cores at 100% you'd see reduced battery life on the iPad 2 vs. the iPad 1. Granted you'd also see better performance on the iPad 2.
Video playback is obviously an important function of these new tablets so we put together a H.264 decode playback test as well. For this test we transcoded a copy of Quantum of Solace from a 1080p BD source down to a 720p H.264 using Handbrake's Normal encode profile with one modification. In order to enable smooth playback on the Motorola Xoom we had to disable b-frames in the encode. The results are below:
The iPad 2 consistently lasted longer than the original iPad in our video playback test. The Xoom however did noticeably worse. Unfortunately only a portion of the H.264 decode pipeline is accelerated by NVIDIA's Tegra 2 in this test. When playing back anything more strenuous, portions of the pipeline are handled by the CPU cores in software. If you were to enable b-frames the Xoom would not only stutter but its battery life would drop to around 6 hours.
On the iPad 2 its Cortex A9s are mostly powered down during this test, on the Xoom the A9s are helping with the heavy lifting for video decode and as a result we see lower battery life. Kal-El is expected to address this issue head on.
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Anand Lal Shimpi - Monday, March 21, 2011 - link
The Xoom review was really written from the perspective of an iPad alternative, while I felt like we covered much of what made the iPad 2 different in our preview and wanted to focus on the bigger picture in the review.The Xoom's multitasking and notifications I believe make it easier to integrate into my workflow, but still not perfect. However Apple has been ergonomics than the Xoom, seemingly better (non-Flash) webpage compatibility, better stability and a smoother UI so it's a tradeoff.
Personally, I'd probably carry the iPad 2 thanks to improved ergonomics (especially with a smart cover) and non-smooth UI frame rates do bother me. But given my workflow neither is sufficient for me to use exclusively when traveling. That's why I mention that both camps have things to work on, whichever gets there first should get your money if you're really on the fence.
Take care,
Anand
Death666Angel - Sunday, March 20, 2011 - link
How do you get to the number in the chart? It would make sense to use the average of all 4 displays, but you don't seem to do that:406 + 409 + 352 + 354 = 1521
1521 / 4 = 380,25 ~ 380
Am I missing something here?
Also, the contrast should be 861:
966 + 842 + 778 + 859 = 3445
3445 / 4 = 861,25 ~ 861
Black levels should be better however:
0,42 + 0,45 + 0,49 + 0,41 = 1,77
1,77 / 4 = 0,4425 ~ 0,44
kmmatney - Sunday, March 20, 2011 - link
The point of having the numbers separate was to show the difference between the WiFi and "WiFi+3G" versions.Death666Angel - Monday, March 21, 2011 - link
And my question wasn't about that at all. The numbers in the actual charts they use for comparison against the iPad1 and the Xoom are not corresponding to any of the 4 distinct iPad2s. So I was wondering where they got the numbers from, if they averaged them or whatnot. If they did average them, then they made a few mistakes in the process. :-) If they got them through some other means it would still be interesting to know which they used.buff_samurai - Sunday, March 20, 2011 - link
speaking about workflow.
I am running a small consulting company for food/pharma industry, my expertise is in analytical instrumentation. Right now I'm using a beefy PC for CAD/backups and IP4/ipad for everything else: emails, project management, crm and documentation all squeezed into a small and portable device (terminal).
Although I am not 100% happy with exchange support in iOS, security, syncing etc I see myself more efficient then ever and that simply means more time/money in my pocket.
Lets try a common scenario: in a car, take a call, pull over, grab a laptop from a bag, power up, check some details, email couple of pdfs and do all that with customer hanging on the phone. Repeat the whole thing 10 times or more - you will see where I am coming from. Or try to carry your laptop around any mid size production line, control room and boardrooms and impress other engineers with questions like: 'where can I plug my laptop' at the same time.
I can understand that for most of heavy laptop users ipad is just useless but lets face the fact that there are millions of professionals on the road and all they care for is better response time and flexibility.
I could spend hours listing applications where no PC (portable or not) can match a tablet but the bottom line is: when moving to new tech we need to overcome our habits first. ipad, xoom and other are like a nice and shiny screwdriver but you will never find a use for it with pockets full of nails. That means no reviewer should ever comment on any device without actually making it a primary tool for couple of months: and if there is no time/money for it - just focus on things that are traceable or you may use your reputation.
darwiniandude - Sunday, March 20, 2011 - link
I always love Anandtech reviews, they cover 'everything' really well, advantages and flaws with equal gusto.Thanks!
Two points:
1) Page 19 I think you're referring to iDisk, not iDrive. Doesn't really matter unless someone trys to Google it.
2) With regard to web browsing, I know you're comparing these units as shipped, but I strongly recommend pro users consider 'iCab' from the AppStore, I don't use Safari much anymore. Propper tabs, full screen, downloading, browser user agent ID spoofing, way more powerful. Scroll pad to quickly navigate huge pages, gestures etc. Tt's very anti-iOS in that it's insanely powerful rather than designed to be simple, but I love it, specifically options like 'open bookmark in new tab' and 'open links from different domain in new tab' very customisable, plugins, blah blah blah. Anyway. It has Desktop style tabs. I wouldn't suggest you change the article, or review this or other 3rd party browsers because it's kinda beyond the scope of the review of the device, but it would be nice if people knew there were alternatives to give a more desktop style (still sans-flash) browser.
pja - Sunday, March 20, 2011 - link
I have really wanted an iPad ever since they were released. Several months ago I had the money (the previous barrier to acquisition) so I went looking. I didn't want the 3G version, WiFi would be fine. But I knew I would not be happy unless I got the one with maximum ram. Well in Australia that was going to cost me over AUD1,000 (I thought they were much cheaper :-( ).Just before this I had built myself a new desktop with an AMD processor and graphics card; see I'm a fan of AMD (but not a bigot). So might I be better off with a netbook rather than an iPad. AMD had recently released the Brazos range. So I started to do some research.
The result was my purchase of a Toshiba NB550D (the sexy orange one) which is a "little under-done" with the C50 Fusion Processor, only 1 Gb of memory and Windows 7 Starter. I have upgraded the memory to 2 Gb (still not enough) and installed Windows 7 Home Pro.
The Toshiba is about the same size as an iPad but is much more functional, it has all my desktop PC's apps installed (particularly my favourite text editor (EditPlus), my browser (Firefox) and all the same bookmarks, etc. etc.) so when I travel I have everything I need and I didn't need to learn how to use new software.
I still think the iPad is a great bit of gear but that's when I use the right side of my brain. My left side says "where's the value proposition?" We are all different but for me the left side of my brain always tends to win over the right side. I am very happy with "my" iPad alternative; more memory and the C-350 processor would be good (but not the larger form=factor that seems to entail). Oh! I forgot to say that the total cost of the Toshiba (including hardware and software upgrades was about AUD675 - more than AUD325 saving!
Regards,
Peter
Deepcover96 - Sunday, March 20, 2011 - link
Great review. Anandtech's reviews are always well worth the wait. They are always thorough and I always learn something. I agree that it is a luxury device and it is hard to justify it for getting work done. I still purchased an iPad 1. I recently sold it to buy the iPad 2, as soon as I can find one. I do think you downplay how important the app selection is on iOS as compared to Android.name99 - Sunday, March 20, 2011 - link
Reading the summary of what all three authors think of iPad feels to me like someone who buys an iPod because it has calendar and contact functionality, and then is upset/surprised that it isn't a Palm.iPad is not a REPLACEMENT for a laptop/desktop, it is an AUGMENTATION. You use each for what they are good at. If you find yourself spending most of your time traveling and you need a full-featured computer during that time then, sure, adding iPad to the mix is stupid. But if you already have a laptop, and can afford it, iPad makes certain tasks a lot more pleasant.
For my part, for example, my primary use for iPad is reading technical PDFs using Good Reader. I could read these on a laptop, but the keyboard really gets in the way (not to mention that the aspect ratio of the screen is inappropriate). If you don't do much reading of technical PDFs, this might seem dumb to you --- but I DO spend many hours a day reading these PDFs and I appreciate a tool that does the job properly, just like a professional carpenter doesn't use a $5 saw he bought at Walmart.
The future of computing is not one device that does everything; it is multiple devices all optimized to a particular human form factor, that all work together --- an iPod nano AND an iPhone AND an iPad AND a laptop AND a desktop. Criticism of something germane to this vision is legitimate and sensible (and Apple's flailing regarding how much of the file metaphor it wants to present to users is a legitimate part of this criticism.) But complaints whose primary structure is "this device doesn't work exactly like a device I already own" is just stupid --- like complaining that a bicycle isn't a car.
It's perfectly reasonable to say that you don't have a use for a certain class of device, especially because you already use something more powerful. I, for example, have no use for a Tivo or a video streaming devices like WD Live or Roku --- I have a full-fledged computer hooked up to my TV. But it is unreasonable to go further than that, and I've observed plenty of non-techy people who are very happy with their WD Live's or Tivos.
It's even more unreasonable to complain that "Tivo sucks because it doesn't play DVDs".
Use some sense. Don't keep trying to use iPad for things it is no good at. Keep in the bedroom, and use it to read, or to look up something quickly on the net, or to play a movie just before you go to sleep. Don't be insane and try to write a novel on it.
pja - Monday, March 21, 2011 - link
"iPad is not a REPLACEMENT for a laptop/desktop, it is an AUGMENTATION. You use each for what they are good at. If you find yourself spending most of your time traveling and you need a full-featured computer during that time then, sure, adding iPad to the mix is stupid. But if you already have a laptop, and can afford it, iPad makes certain tasks a lot more pleasant."You must have either too much cash or too much time on your hands or both. A good business class laptop is AUD1,500+ while a top of the range iPad is AUD1,000 + here in Australia.
It seems to me when you think about the iPod with your left brain there is very little functionality that a good netbook does not do both better and cheaper. However, I would agree that when you let your right brain rule then all of a sudden the iPad becomes a irresistible thing that you must possess. Unfortunately for me my left brain clicks in when I pull out my credit card.
Peter