The CPUs

Like the iMac and MacBook Pro before it, Apple has blessed the MacBook Air with Intel's 32nm Sandy Bridge family of CPUs. Despite being named similarly to the Core i5/i7 in the MacBook Pro, only dual-core Sandy Bridge is offered in the MacBook Air. The cases are simply too small to accommodate any 32nm quad-core parts.

Also NVIDIA is completely out of the picture here. While the previous generation MacBook Air used an NVIDIA chipset with integrated GeForce 320M GPU, Apple is relying entirely on Sandy Bridge's processor graphics this round.

Apple opted for ultra low voltage Sandy Bridge CPUs all with a 17W TDP. The previous generation used a 10W part for the 11 and a 17W part for the 13, but remember those figures didn't include NVIDIA's GeForce 320M which is good for at least another 14W under load, and probably a watt or two with the GPU idle. The 17W SNB parts include memory controller and GPU, leaving only the chipset at 3.4W. Max power consumption is likely lower on the new MBAs, although typical power consumption could be higher as Sandy Bridge cores are significantly faster than the Core 2s used before.

There are three different CPUs Apple offers in the new MacBook Air lineup:

2011 Apple MacBook Air CPU Comparison
1.6GHz Core i5 1.7GHz Core i5 1.8GHz Core i7
Available in 11-inch (default) 13-inch (default) high-end 11-inch (option)
high-end 13-inch (option)
Intel Model Core i5-2467M Core i5-2557M Core i7-2677M
Cores/Threads 2/4 2/4 2/4
Base Clock Speed 1.6GHz 1.7GHz 1.8GHz
Max SC Turbo 2.3GHz 2.7GHz 2.9GHz
Max DC Turbo 2.0GHz 2.4GHz 2.6GHz
L3 Cache 3MB 3MB 4MB
GPU Clock 350MHz / 1.15GHz 350MHz / 1.2GHz 350MHz / 1.2GHz
Quick Sync Yes Yes Yes
AES-NI Yes Yes Yes
VT-x Yes Yes Yes
VT-d No Yes Yes
TDP 17W 17W 17W

All three parts support Hyper Threading and Quick Sync, although the latter remains mostly unused in OS X. The 11 comes with a 1.6GHz part by default while the 13 ships with a 1.7GHz chip. Both can be upgraded to the same 1.8GHz Core i7, a big change from last year's lineup where even the upgraded 11-inch model was slower than the base 13.

Turbo is fully supported at the default Intel ratios (more on confirming this later). This is actually a pretty big deal because it means that for single threaded applications you actually get similar performance to a MacBook Pro. It's only in the thread heavy stuff that the Pro machines will pull away.

The default chips for both systems comes with 3MB of L3 cache. The majority of quad-core parts only have 6MB of L3 and seem to do just fine, so I don't expect that this is too big of a deal. The upgraded 1.8GHz CPU comes with an extra MB of cache.

You'll see this in the performance section but there's just no comparison between the CPUs in the 2011 MacBook Air and what Apple shipped last year. If the MacBook Air wasn't fast enough for your last year, the 2011 models should change that.

Introduction Testing Turbo
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  • name99 - Thursday, July 28, 2011 - link

    "
    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.
    "

    This is a horribly misleading way of stating the issue. It implies that Apple or the chipset or something are somehow defective, in only delivering 50% of the available performance.
    The ACTUAL problem is the 802.11 MAC & protocol, which wastes about 50% of the available bandwidth doing god knows what. The packets that go out, go out at of order 270Mbps, but 50% of the time packets are not going out.

    This would be a good topic for a future AnandTech article --- just what the hell is the 802.11 MAC doing that wastes so much airtime?
    A useful issue to discuss in the same article is the following:
    I read once that there was an advanced option in the 802.11n MAC that reduced this wasted time to only (hah!) about 25%, but I have never seen details on this (and I have looked). Is it real? If it is real, does anyone support it?
  • ninjaquick - Thursday, July 28, 2011 - link

    The relevance of SSDs is really only synthetics and low ram high cache situations. I do like seeing these get beat out squarely by an i3 in pretty much everything else in the win7 tests.
  • bji - Friday, July 29, 2011 - link

    How do you draw that conclusion about SSDs?
  • KPOM - Friday, July 29, 2011 - link

    They only get beaten out by the i3 in the 3D tests, which are driven by the GPU, so it's more fair to say that the HD 3000 gets beaten out by a discrete graphics adapter, which is no surprise. The Airs handily beat out the i3 in the CPU-intensive benchmarks.

    I've used an SSD since November 2008 and won't go back. I still need to use a HDD-equipped machine at the office, and I can't stand how long it takes to restart, shut down, or do anything disk intensive. The SSD made the Core 2 Duo-equipped MacBook Air tolerable in a world of i3s, i5s, and i7s. The Sandy Bridge-equipped MacBook Air with SSD makes it that much better.
  • Baron_Fel - Thursday, July 28, 2011 - link

    When are you guys going to review the new Vaio Z? I want to know if that external GPU is worth anything.
  • TwoStreetCats - Thursday, July 28, 2011 - link

    I'm a very happy owner of the 2010 11" version and have to say that the form factor was the primary draw for me as I travel quite a bit. It fits quite nicely in the hydration pocket of my backpack and I hardly know that I have it with me.

    The only thing that is occasionally frustrating is the vertical resolution as the article mentions.

    However, I use Mac Screen Rotate to rotate the screen and touchpad for portrait viewing when browsing or viewing pdf's and this problem is solved. If size and weight are serious factors for you, I highly recommend trying this out with the 11" before you decide that you need the 13".

    www.macscreenrotate.com
  • bji - Friday, July 29, 2011 - link

    If the TDP of the processor + graphics is 17W, why does the Macbook Air even need a fan?

    My Panasonic Y2, which I still use because I can't find a laptop I like better (just sold a Sager NP5160 that I only owned for 2 months because I couldn't stand the fan noise or the horrible keyboard), has a 22 W max TDP on just the Pentium M 1.4 Ghz processor. Probably the crummy Intel integrated graphics doesn't add more than a few watts but together they must be at least 25 W.

    And yet, the Macbook Air, with a 17 W processor + graphics combined, has a fan. There is plenty of aluminum in the body of the Macbook Air to act as a heatsink, why does Apple even need to put a fan in there? If the Y2 can go fanless, surely the Air can.
  • bji - Friday, July 29, 2011 - link

    OK, turns out the Pentium M in my Panasonic Y2 is the 10 watt Pentium M 738, not the 22 watt Banias Pentium M.

    The Intel 855 GME chipset is listed at 3.2 W.

    Is it really the case that 10 W can be fanless but 17 W cannot?
  • tipoo - Friday, July 29, 2011 - link

    Might be possible in 17w, but it already gets pretty hot WITH a fan.
  • hellknight - Friday, July 29, 2011 - link

    I couldn't believe that Intel included AES instruction set in such low voltage chips. Even the base model has those.. This is something very great.. It would be great for all Truecrypt users..

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