The GPU Comparison

If you had asked me last year I would've told you that Apple clearly values GPU performance more than CPU performance—and I wouldn't be far off the mark. Apple went to great lengths to use the best of the entry level GPUs and paid no mind to the fact that the 13-inch MacBook Pro, Mac mini and MacBook Air all used much older Core 2 Duo CPUs while the competition was busy shipping Core i3/5/7s.

This year is the year of the CPU however. The entire MacBook Pro lineup gets Sandy Bridge CPUs and as a result they all get Intel's new HD Graphics 3000. Here's a die shot of Sandy Bridge:

Note that the GPU core is integrated on-die. There are actually two versions of Intel's HD Graphics available on Sandy Bridge, but all current mobile versions of SNB come with the 3000 model. What does the 3000 offer you? Twelve scalar execution units (EUs) running at a base clock speed of 650MHz. The GPU can also turbo up depending on available TDP. The max frequency is somewhere between 1.2—1.3GHz depending on the processor SKU.

Being basically desktop replacements, the 15-inch and 17-inch MacBook Pros also include a discrete GPU. This round they both use AMD hardware and the options are below:

Discrete GPU Options
  AMD Radeon HD 6490M AMD Radeon HD 6750M
Manufacturing Process 40nm 40nm
SPs 160 480
Texture Units 8 24
ROPs 4 8
Core Clock 800MHz 600MHz
Memory Bus Width 64-bit 128-bit
Memory Clock 800MHz 900MHz
Frame Buffer 256MB GDDR5 1024MB GDDR5

The entry level 15 uses a Radeon HD 6490M while the upgraded 15 and the 17 both use a Radeon HD 6750M. The difference between the two GPUs amounts to compute horsepower, memory bandwidth and available frame buffer. With only a 256MB frame buffer the 6490M is insufficient for high performance at larger resolutions (courtesy of an external display). The 6750M is paired with 1GB of GDDR5 and thus has no problems smoothly driving a 27-inch 2560 x 1440 panel. The new GPUs now only use a x8 connection to the SNB CPU compared to the x16 from last year's models. Remember Sandy Bridge has a x16 PCIe controller on-die. The controller can be split into two x8s or 1 x8 and 2 x4. In this case one of the x4 ports is used for Thunderbolt, leaving 4 unused lanes and a x8 for the GPU. I don't expect this move will have a noticeable impact on GPU performance.

The 13-inch MacBook Pro has absolutely no GPU options, all you get is the on-die Intel HD Graphics 3000. Based on what we saw in our original mobile Sandy Bridge review this should mean that GPU performance between the two stays the same. Intel's HD Graphics 3000 is about the performance of a GeForce 320M, the latter is what was used in last year's 13-inch MBP.

Half Life 2: Episode 2 (Mac OS X)

For Starcraft II performance we brought over our two benchmarks from our PC CPU and GPU reviews. We don't have FRAPS availalble under OS X so we resort to measuring lowest instantaneous frame rate at a couple of points.

The two tests focus on different aspects of SC2 gameplay. The GPU test looks at general unit management performance, which tends to be less CPU bound and more GPU bound. The CPU test looks at performance during a very large battle which, as you might guess, is largely influenced by CPU performance. 

Starcraft II—AT GPU Bench (Mac OS X)

Starcraft II—AT CPU Bench (Mac OS X)

Under OS X, the new HD Graphics 3000 GPU is actually about the same performance or even faster than the 2010 13-inch's GeForce 320M. Remember that Apple does a lot of its own driver writing under OS X and the SNB GPU received some TLC from Apple in the form of very well optimized drivers.

World of Warcraft (Windows 7)

Left 4 Dead (Windows 7)

Under Windows running WoW the situation is quite different and I'm not entirely sure why. Either Apple is very aggressive with driver optimizations under OS X or there's some other funniness happening under Windows (more on this later).

I did notice some bouts of instability with the 13-inch MacBook Pro as well as minor graphical corruption on the screen. Early on whenever I'd boot the system up I'd get a copy of the mouse cursor in the upper left of the screen.

15-inch MacBook Pro GPU Performance

Next up is the 15-inch MBP gaming performance comparison.

For 15-inch users the Radeon HD 6490M is pretty much the same speed as last year's GeForce GT 330M (if not marginally faster). The Radeon HD 6750M however is a lot faster. In fact, the performance improvement and increase in frame buffer you get with the 6750M is well worth the upgrade. If you're buying a 15-inch MacBook Pro and plan on gaming or using a high-res external display, get the 6750M.

Half Life 2: Episode 2 (Mac OS X)

Half Life 2: Episode 2 (Mac OS X)

Half Life 2: Episode 2 (Mac OS X)

Starcraft II—AT GPU Bench (Mac OS X)

Starcraft II—AT GPU Bench (Mac OS X)

Starcraft II—AT CPU Bench (Mac OS X)

Starcraft II—AT CPU Bench (Mac OS X)

6Gbps Performance & SSD Recommendations The dGPU: Killing Battery Life
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  • jb510 - Friday, March 11, 2011 - link

    It would seem to me their is one currently shipping Thunderbolt periphral... A 2011 MBP in target disk mode. Maybe you could drop an SSD in one and do some preliminary testing? Reply
  • jb510 - Friday, March 11, 2011 - link

    damn... wish i could edit that comment originally typed on my iphone... but their doesn't appear to be any way... (misspelling repeated for comedic effect) Reply
  • deadshort - Friday, March 11, 2011 - link

    Thanks for the genuinely informative review. Running both low-load and high-load battery tests is especially helpful to developers, etc.

    One question. You chose the 2.3Ghz/8MB cache system. Was that just 'cuz you swing that way, or do you expect significant performance benefits for some workload you care about? For these machines is it a 10% price goldplate, or a reasonable increment to keep these CPUs fed? I am seriously interested....
    Reply
  • Brian Klug - Friday, March 11, 2011 - link

    I can speak for myself at least, but part of the reason for the 2.3/8 MB system choice was that it's the only preconfigured (Apple Store available) configuration that comes with the anti-glare display.

    Essentially, if you're a customer walking into the apple store and don't want the glossy/glare display, you're immediately forced into buying the highest-specced (and most expensive) MacBook Pro. It's frustrating because the only way to get lower specced systems is BTO online.

    Obviously we got these systems on launch date to immediately start working, and that was the reason for the 2.3 choice.

    -Brian
    Reply
  • synaesthetic - Friday, March 11, 2011 - link

    You know, I don't get this thin crap. I really don't.

    I mean, I can understand it. From a purely aesthetic point of view. Sort of, anyway.

    I'm sick of "thin" gadgets with weak performance and fragile builds. Thick gadgets means more tech fits inside. My HTC Glacier is quite thin, and you know what? I wish it was thicker. It'd be easier to hold onto, and HTC could have put a bigger battery in it!

    Stop making things so stupidly thin. Instead of driving the miniaturization of components on "thin," why not take that same miniaturization power and make things a bit thicker... with more power/cooling/battery inside?

    Thin may be sexy, but powerful is even sexier!

    Then again, Apple's never really cared to broadcast the specs of their devices, hoping instead to gloss over it to such a degree that nobody questions paying ridiculously inflated prices...
    Reply
  • Marc B - Friday, March 11, 2011 - link

    I am finally buying my first MacBook this year, and I am 70/30 leaning toward the 15" MBP. The 17" version has the high res screen and express port, but the 15" MBP is lighter/smaller and has the SDXC reader. Will the Thunderbolt port will provide enough throughput to allow simultaneous in/out?

    I am using this to log HD video on location, and was wondering if the express port is no longer necessary to use with a small ESATA array now that you can have high speed storage in and out using the Thunderbolt port.
    Reply
  • Belard - Friday, March 11, 2011 - link

    If Apple is pushing their notebooks to be more and more Desktop replacements...

    Where is a docking bay to handle all the connectors? How hard for a single connector to handle everything?

    Lenovo sells about 3 different Docking units $130~300 for their regular Thinkpad line (ie: NOT Edge or L/SL series).

    We have a few users who use them. Comes to the office, drop the notebook into the dock and turn it on, not a single cable to be attached. They include 4 USB ports (or more), PS/2 ports, HDMI and DVI ports, Ethernet and of course charge up the battery.

    So one user would have to plug in 7 cables everyday if he didn't have a dock... like his keyboard, wireless desktop mouse, 21" display, various printers and devices, etc.
    Reply
  • name99 - Friday, March 11, 2011 - link

    " I still haven't figured out how to actually grab SINR out on here, all I can see for the moment is just RSSI. "

    Apple's Airport Utility does give you part of what you want.
    If you open it, go to "Manual Setup", see the summary page, and click on where it says "Wireless Clients: 2" (or 3 or whatever) you will be given a page that, for each connection, shows their signal and noise levels (along with a graph).

    Of course this doesn't exactly have any bearing on what we are discussing, because the numbers that are presented are the intermediate term SINR values, relevant to shadowing but not to fading. The numbers that are relevant to fading (and thus to MIMO tricks) change on a millisecond time scale, and so what one really wants is an indication of their standard deviation, along with other info like the connection diversity. This is all way more geeky than Apple (or any other consumer company) is going to provide.
    Reply
  • humunculus - Friday, March 11, 2011 - link

    Any chance you could run a few of the tests on the 2.0 and 2.2 GHz models. I am interested in how much performance difference there is between the 2.2 and 2.3 GHz 15 inch Macbook Pro models. It is hard to assess if the 10% cost increase is warranted. Thanks Reply
  • Belard - Saturday, March 12, 2011 - link

    The $400 price difference is for the extra 200mhz (Apple values that at $250 - these are notebook CPUs, so pricing from intel is a factor)

    And then $150 to sometimes double the performance of the GPU for games.

    Oh, and an extra 250GB of HD space (which is about $5 in the real world).
    Reply

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