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 dGPU: Killing Battery Life
The 15 and 17-inch MacBook Pros have a discrete GPU that only turns on if you fire up an application that really needs it—at least that's how it is supposed to work. In practice, the discrete GPU takes over control if your application uses any one of a number of frameworks—and some of the time, the dGPU simply isn't necessary.
Case in point, launching Chrome won't trigger a dGPU switch but the moment it encounters Flash the discrete GPU will take over. The bad news is that even if you close all Chrome windows, the dGPU won't power down until you quit chrome entirely. The same is true for Photoshop. Launch the application and you're still on the iGPU. Actually open up an image and the dGPU takes over. Even if you close all open images and just leave the Photoshop application open, the dGPU won't relinquish control. FaceTime and anything using the integrated camera also require the dGPU, despite it being totally unnecessary.
If you connect any external display to the 15 or 17-inch MacBook Pro that also forces the dGPU on, at which point both the integrated panel and external display are driven by the dGPU. There is no funny frame buffer copying going on, both the integrated and discrete GPUs have their own connection to the display.
Apple also fails to provide a way of turning off the dGPU by default—the best you can do is shut off the iGPU and just use the dGPU entirely. Thankfully Cody Krieger's gfxCardStatus tool gives us exactly what OS X does not. Version 2.0.1 adds support for the 2011 MacBook Pros.
I'm going on and on about the dGPU because it's state can seriously impact battery life. The numbers below should help put that in perspective for you:
| Impact of Discrete GPU on Battery Life | ||||
| 15-inch 2011 MacBook Pro | Light Web Browsing | Flash Web Browsing | ||
| Integrated GPU (Intel HD 3000) | 8.85 hours | 7.03 hours | ||
| Discrete GPU (AMD Radeon HD 6750M) | 5.67 hours | 2.97 hours | ||
Even just browsing the web, the dGPU being on drops battery life by 35—60%. Under full CPU load I suspect the percentage difference would be smaller, but still significant. The worst part of this all is that without gfxCardStatus you can negatively impact battery life by doing something completely innocent like accidentally leaving an application open. Given how much OS X is tailored to simply closing windows when you're done with them and not quitting applications, an overly aggressive dGPU can really be an issue.
Thankfully we do have gfxCardStatus but there's honestly no reason Apple shouldn't include this functionality with OS X from the start.
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iwod - Friday, March 11, 2011 - link
iPad is only just starting to sell and iPhone still has lots of space to grow. The trend is Apple are making more units and more money from ARM specific products.Nvidia has just recently stated that Project Denver will be ARM 64 bit. And aiming at HPC and Desktop. Full Compatible with current ARM instruction set.
Currently Apple must have a ARM version of Lion testing, and few years down the road, they could switch their Mac over to ARM 64 bit. Using a single Instructions Set for their whole product line.
For some reason i have been thinking that Apple and Intel aren't doing too well together like anand has felt. I dont think Thunderbolt is any indication of their current relationship. it is merely they have been working on it for such a long time, no one wants to lose our at the end.
Of coz it could have been the other way round x86 moving into iPhone, although that depends how much intel is willing to bend towards apple.
jbh129 - Friday, March 11, 2011 - link
Anand,Can you guys run your high-end 15 through the Windoze tests that were used on the 13?
Thanks
tajmahal42 - Friday, March 11, 2011 - link
Hello guys!First, I have to say this review is really awesome, as usual! Just what I was hoping for. The thoroughness and practical sense of your reviews continues to amaze me every single time.
For the 13" MBP, you mention "bouts of instability". Can you elaborate on that? Stuttering? Crashes? In what way do you notice that instability? I'm a little concerned now.
tno - Friday, March 11, 2011 - link
+1alent1234 - Friday, March 11, 2011 - link
my wife has been bugging me about our wifi since we moved and get a poor signal in a lot of the new apartment. told her i can get a new router with 3 antennas but we will also need a new laptop as well with the antennas to take advantage of it.which brings me to my question. i know the 15" model has the 3 antennas. does the 13" do MIMO as well?
tipoo - Friday, March 11, 2011 - link
They all use the new card.By the way, have you tried switching wifi channels, or installing DD-WRT and boosting signal? Even so, you don't need a new laptop after getting a new router if signal strength was the only problem.
alent1234 - Friday, March 11, 2011 - link
i'll try that, thxa lot of wifi around me these days. we only have work laptops now so that would be our only personal computer if we bought one. i was looking for the cheap SB models when they come out
name99 - Friday, March 11, 2011 - link
"told her i can get a new router with 3 antennas but we will also need a new laptop as well with the antennas to take advantage of it."This is not completely true. A base station with multiple antennas CAN do the equivalent of phase-array beam steering to direct most of the output power towards the target laptop. The laptop will thus see a stronger signal, and one of the better modulation schemes (eg 64-QAM 5/6) can be used rather than one of the weaker schemes. Thus your laptop, even if it has only one (or two) antennas can still see better performance.
Note, this is a theoretical possibility. I do not know the current state of the art in how well base stations utilize the various forms of transmit diversity that are available. And no review ever seems to talk about this stuff, either by testing how well the kit works with a single antenna device, or by talking to the manufacturer about what's in their product.
Brian Klug - Friday, March 11, 2011 - link
The 13" does have 3x3 MIMO as well, the exact same broadcom solution as the 15" I tested extensively.-Brian
7Enigma - Friday, March 11, 2011 - link
Anand and crew,I am very disappointed with the battery life numbers in this review. This is the first review of a laptop where it appears you have used a 3rd party app (Cody Krieger's gfxCardStatus tool) to significantly inflate the numbers of the new 2011 systems. 35-60% by your own numbers back on the discrete GPU battery life page, which you then fail to report in the battery life tables later on!
When you are tasked to review a system (especially an Apple product I might add) it should be reviewed as is, with no tweaking or 3rd party add-ons to boost performance/benchmarks. When have you EVER installed an add-on for a Windows-based laptop to improve performance/life? I can't think of one.
At best this was a simple oversight where you have benchmark numbers WITHOUT the gfxcardstatus, at worst this was a cover-up job which I have always argued in the forums against and on your site's behalf.
Please update the tables to show what a stock newly-purchased laptop at the Mac Store would deliver.
I am very disappointed in this coverage.