The MacBook Pro Review (13 & 15-inch): 2011 Brings Sandy Bridge
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on March 10, 2011 4:17 PM EST- Posted in
- Laptops
- Mac
- Apple
- Intel
- MacBook Pro
- Sandy Bridge
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.
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.
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.
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.
Facebook
Twitter
RSS
198 Comments
View All Comments
Anand Lal Shimpi - Friday, March 11, 2011 - link
Thank you for reading them, comments like this really do make it all worthwhile :)You wouldn't believe how much time was spent making sure Apple wasn't doing something funny with the max turbo frequencies. At the end of the day it was a non-issue, but we had to be sure.
Take care,
Anand
Ryan Smith - Friday, March 11, 2011 - link
Just to add some technical background to this, it's actually quite complex to get a CPU speed reading on modern CPUs. Mac OS X's Sysctl reports the base speed of the processor, regardless whether Turbo Mode is active or not. So on the 15" low-end QC model you will always see 2.3GHz.To actually read the instantaneous speed of any given core, you need to peek at the CPU itself and count the cycles - Intel actually has a handy document detailing an algorithm to do this(1). The issue with that is that it requires peeking at the Model-Specific Registers (MSRs), which require Ring 0 access; or in other words you need a broker at the driver level to do it.
Linux already does this (/proc/cpu/0/msr), and on Windows it's fairly trivial to load a driver alongside an Admin-level application to do this(CPU-Z, etc). Under Mac OS X this requires installing an Extension (at least as far as I know) which gets messy. If you don't go through this process you'll never be able to read the core speeds accurately, which is why there's virtually no Mac software capable of this.
Fortunately MSR Tools exists, and it has a 32bit extension to allow it to peek at the MSRs. The right answer of course is always the last answer you try, so this was only after trying several other ways of calculating the CPU speed and a couple different OS-agnostic benchmarks to try to rule out OS differences.
1) http://download.intel.com/design/processor/applnot...
tno - Friday, March 11, 2011 - link
+1I've been planning to plunge into Mac ownership for sometime, especially with grad school looming I really want something that's more comfortable to work on than my netbook but still fairly portable. This review really helped me gauge whether it was worth putting in the extra cost for a 2011 13" MBP or settle for a discounted 2010.
So am I all set? Hardly! Now I need to see what the 2011 13" MBA has to offer! I'm praying that cost stays roughly the same and a move to a ULV SNB leads to 12+ hour battery life and a similarly huge leap in performance as the move lead to in the MBP. I am a sucker for lightweight form factors.
This article is also the first one to make me ever consider the 15" MBP. I have been fairly opposed to the bulk but the performance is quite something. If I went that route then I would probably have a C2Q, water-cooled, ATI and SSD driven rig to put up on AT forums. Taking offers!
tno - Wednesday, May 4, 2011 - link
Rezzing a dead thread! I bought the 13" MBP! $999 at MicroCenter, too good to pass up! So . . . who wants my rig?JasperJanssen - Saturday, August 6, 2011 - link
I, on the other hand, have gone the other way. My MBA13 is being put together in China now.ltcommanderdata - Thursday, March 10, 2011 - link
A great review. I do have some additional questions though. First, given Apple was the instigator of OpenCL, it'd be great if you could run some OpenCL benchmarks. Are the Sandy Bridge MacBook Pro's disproportionately faster than the Arrandale MacBook Pro to indicate that OS X has CPU OpenCL drivers that can take advantage of AVX? Probably not, and this will hopefully come with Lion. Given nVidia's GPGPU push can the HD 6490 still keep up with the 330M GT in OpenCL? How does the HD6750 do?http://www.bit-tech.net/hardware/graphics/2011/01/...
"'[Intel] will be releasing OpenCL graphics drivers to developers during the course of 2011. [Intel] continue to evaluate when and where OpenCL will intercept various products"
And is there secret Sandy Bridge IGP OpenCL support? Bit-tech got a quote from Intel that Sandy Bridge IGP OpenCL support was inbound sometime this year and if anyone would be motivated to get it done it'd be Apple.
And finally, does Apple now support hardware H.264 decoding on ATI or Intel GPUs? Previously, only a few nVidia GPUs were supported in Snow Leopard, such that the Arrandale MacBook Pro actually had to power up the 330M GT to decode H.264 wasting power compared to the perfectly fine Arrandale IGP if Apple just wrote the drivers. Do the new Sandy Bridge have the ATI GPUs doing H.264 decoding now, is the Intel IGP supported, or in the worst case is no H.264 hardware acceleration available now that nVidia GPUs are gone? Perhaps lack of hardware H.264 decoding is what makes the FaceTime HD CPU usage so high? QuickSync is only accelerating the encoding phase?
Anand Lal Shimpi - Friday, March 11, 2011 - link
Some answers:1a) I don't know of any good GPU based OpenCL tests under OS X at this point. I'm not even sure if Apple's Intel HD 3000 driver supports OpenCL.
1b) Intel mentioned SNB's GPU technically supports OpenCL however there are no plans to release a public driver at this point.
2) Hardware H.264 decoding is enabled on the 2011s and it is used while FaceTiming, at least according to Apple.
Take care,
Anand
ltcommanderdata - Friday, March 11, 2011 - link
Thanks for the reply.http://www.macupdate.com/app/mac/33632/smallluxgpu
In regards to OpenCL testing, most people in OS X seem to use SmallLuxGPU which is an OpenCL raytracing benchmark. I don't have much experience with it, but it might be worth a try.
In regards to hardware H.264 decode, do you know if the IGP is doing it or does the discrete GPU still have to be powered up as in the 2010 Arrandale MacBook Pros?
Thanks
Anand Lal Shimpi - Friday, March 11, 2011 - link
It's my understanding that the IGP can do the decoding, although note that while FaceTime is running the dGPU is enabled by default.Good call on SLG, I had forgotten about that :)
Take care,
Anand
secretmanofagent - Thursday, March 10, 2011 - link
Hello authors,On one of the pages, you mentioned this:
"This isn't Mac specific advice, but if you've got a modern Mac notebook I'd highly recommend upgrading to an SSD before you even consider the new MacBook Pro. I've said this countless times in the past but an SSD is the single best upgrade you can do to your computer."
Is there an article where you recommend the best update for my model? Should I even bother with the drive? I realize the X3100 is going to still hamper any sort of graphical performance, but wondering if it's worth the effort.
Out of curiosity as well, would a Time Machine restore be possible if you update the drive?