SSD Performance

Last year's MacBook Air was the first Mac to ship without a mechanical hard drive or an option to install one. Using a custom form factor, Apple partnered with Toshiba (and later Samsung) to build value SSDs for the MacBook Air line.

Although Apple has tested solutions from Intel, Marvell and SandForce, to date it hasn't opted to ship any of them to market. Toshiba and Samsung offer much better pricing and don't mind being silent members of the supply chain. There are also reliability benefits. While Toshiba and Samsung may not perform as well as the aforementioned controller makers, they've definitely had fewer issues.

My 13 had a Toshiba based drive while my 11 had a Samsung drive. You can tell what controller you have by looking at the model string in a System Report from your machine. The SM prefix indicates a Samsung drive while the TS indicates Toshiba:

Both controllers are limited to 3Gbps operation (neither company has released a 6Gbps controller) but performance does vary pretty significantly between the two:

2011 MacBook Air SSD Performance Comparison
  4KB Random Read (QD3) 4KB Write Read (8GB LBA Space QD3)  128KB Sequential Write 128KB Sequential Read
13-inch MacBook Air (Mid 2011) - Toshiba SSD 18 MB/s 1.65 MB/s 204.2 MB/s 189.5 MB/s
11-inch MacBook Air (Mid 2011) - Samsung SSD 44.6 MB/s 27.2 MB/s 258.0 MB/s 234.4 MB/s
11-inch MacBook Air (Late 2010) - Toshiba SSD 31.1 MB/s 2.49 MB/s 147.0 MB/s 113.0 MB/s

The Samsung drive has much better random and sequential performance, maxing out the 3Gbps interface when it comes to sequential reads.

In regular use I doubt you'd notice a huge performance difference between the two, but if you want the fastest drive you want the Samsung. Compared to last year's MacBook Air (Toshiba) you get a huge boost in sequential read/write performance.

Both drives support TRIM under OS X.

WiFi

Unlike other members of the 2011 Mac family, the MacBook Air retains a WLAN stack with 2 receive and 2 transmit antennas via the Broadcom BCM4322. The WLAN solution in the Air is capable of up to two simultaneous spatial streams, topping out at 270Mbps.

In practice this results in peak performance over 802.11n at around 128.8Mbps. Testing at the same distance I tested the MacBook Pro and iMac at, the results drop to 116.8Mbps.

802.11n Network Performance Comparison
  27-inch iMac (Mid 2011) 15-inch MacBook Pro (Early 2011) 13-inch MacBook Air (Mid 2011) 11-inch MacBook Air (Mid 2011)
Peak Network Transfer Speed 150Mbps 133Mbps 116.8Mbps 116.8Mbps

The new Air also supports Bluetooth Low Energy, although without any Bluetooth LE devices on hand I was unable to test the feature.

The Display: Better than Most, Not as Good as the Pro CPU Performance: A Huge Upgrade
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  • netmask254 - Thursday, July 28, 2011 - link

    It's really surprising to me that the huge random speed difference, and how can Apple tolerate such an inconsistent behavior among different machines? I heard that the buyer will randomly get a Sumsung or Toshiba SSD even for the same model, that's too bad. However, maybe most Apple users don't care about it or don't know it. Reply
  • beginner99 - Thursday, July 28, 2011 - link

    Yeah, especially since you would actually pay an apple premium for knowing what you get. But then these are more priced like windows laptops so they probably had to lower some standards.
    The so called ultrabooks according to rumors might even be more expensive than MBA. IMHO especially the 256 GB version is a bargain (if you get the Samsung ssd). That alone costs you like 400$ if you would manually upgrade a cheap windows laptop.
    Isn't the 4k random read the main thing that prevents stuttering issues ins ssd compared to hdds?
    Reply
  • lyeoh - Thursday, July 28, 2011 - link

    I think the stuttering is more to do with the max access latency.

    You could have a very fast drive that averages 100MB/sec over 1 minute, but if every 30 seconds it "hangs" for one second, you would notice it.

    e.g. for one second your transfer rate drops to 0MB/sec, but for the other 29 seconds it transfers at 104MB/sec.

    That's why many of those benchmarks don't tell you everything about how it feels.

    Same goes for fps you could get 120fps but if what appears on the screen is actually delayed by a 100 milliseconds, it's worse than something that "only" does 60 fps with 5 millisecond delay.

    Not many reviewers test for latency. Anandtech does have some latency tests for a few SSDs, but so far it does not appear to be a standard benchmark.
    Reply
  • KPOM - Thursday, July 28, 2011 - link

    Interestingly, on the MacRumors forum someone posted results of another benchmark that suggested that the Toshiba outperformed the Samsung on random reads and writes, though the Samsung outperform on sequential.

    http://translate.google.com/translate?u=http%3A%2F...

    Anand says the Samsung outperforms on both. Note that this was also the case in the 2010s. Toshibas started shipping first, and Samsungs made their way into the system in January. Apple seems to have carried them over unchanged to the 2011. I wonder what impact supply chain issues (e.g. the tsunami) and legal issues (e.g. Apple's lawsuit against Samsung) have on their purchasing decisions?
    Reply
  • fericia - Monday, August 15, 2011 - link

    My wife's 13-inch one came with SM256... Reply
  • arthur449 - Thursday, July 28, 2011 - link

    Light Web Browsing Battery Life
    13-inch MacBook Air (Mid 2011) - Core i5 2.7GHz

    This message will self-destruct after reading.
    Reply
  • Anand Lal Shimpi - Thursday, July 28, 2011 - link

    Fixed :)

    Take care,
    Anand
    Reply
  • refresh_time - Thursday, July 28, 2011 - link

    Thank you for a very in-depth review.
    I was ordered the i7 13" without needing the bigger ssd, but after reading this, I think i should exchange it for a i5 :D
    All I wanted from i7 was video work on imovie but if there is only about a 10% gain in performance, I think I'm better with i5.. (right?)
    But i read the mba review here (http://www.gadgetreview.com/2011/07/apple-macbook-... and they seem to recommend i7 highly. what do you think?

    I'll use the return money to buy a 1tb hardrive and a nice sleeve
    Reply
  • iwod - Thursday, July 28, 2011 - link

    I think we need something thinner, lighter, and more size to choose from. Not everyone's home can fit a bloody 27" Monitor. Reply
  • ImSpartacus - Thursday, July 28, 2011 - link

    Apple doesn't do low margin products.

    Even if they offered a 24" IPS panel with all the fixings, it would approach $500. It's hard to explain to a customer why they need to spend twice as much as a bargain bin 24" TN panel.

    There aren't a lot of 1440p 27" monitors on the market today for less than $1000, so Apple doesn't run into any comparison problems. The camera, speakers and connectivity features are just gravy.
    Reply

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