Thermals and Power Consumption

The new MacBook Pros have the potential to draw more power than the previous generation. Despite being built on a 32nm process, the new 15 has twice the cores of last year's model—there's no question that it can draw more power under a full load.

I measured maximum power consumption at the wall using the same power brick and a fully charged battery. I chose two high-load scenarios: Cinebench 11.5 and Half Life 2. The former will fully load all CPU cores while the latter ramps up CPU and GPU usage.

Maximum Power Draw—Cinebench R11.5

Under Cinebench the new quad-core 15-inch MacBook Pro draws 70% more power at the wall than last year's dual-core model. This shouldn't be surprising as Cinebench scales nearly perfectly with core count—twice the cores should result in nearly twice the power draw. The scaling isn't perfect since we are dealing with different architectures and a number of factors such as display remain static. The new 13-inch MacBook Pro isn't as worrisome, it has 88% of the power usage of the high end 2010 15-inch MBP and 81% of the battery capacity.

Maximum Power Draw—Half Life 2: Episode 2

The Half Life 2 comparison is not quite as bad, although the new 15-inch MBP still uses 45% more power under full load compared to the previous generation. These numbers tell you one thing: although the new MBP is significantly faster than its predecessor, it can also draw significantly more power. Running the same workload the new MBP shouldn't have any problems lasting as long as the old MBP on battery, but running a more aggressive workload will result in shorter battery life as a result of the higher max power consumption. In other words if you use the higher performance to do more, you can expect your battery to last proportionally less than the 2010 MBP.


The 15-inch MBP uses an 85W power adapter (left) and the 13-inch MBP uses a 60W adapter (right)

Drawing more power also has another unfortunate side effect: the bottom of the chassis gets even hotter than before. I took some crude temperature measurements when I did the 2010 MacBook Pro reviews last year. I pointed an IR thermometer at the center of the bottom of the notebook, right where you'd have your lap, and measured surface temperature in a couple of scenarios.

Surface Temperature—Web Browsing

While browsing the web with tons of windows/tabs open I noticed a small but tangible increase in surface temperature of the 2011 15-inch MBP compared to the 2010 model. Even the new 13 is warmer than last year's 15. Under light workloads none of these temperatures are high enough to really be a problem.

Surface Temperature—Half Life 2: Episode 2

Load up the system however and you start getting into the uncomfortable zone. The new 15 breaks 38C, while the new 13 is actually only marginally warmer than the old 13 thanks to the use of Intel's HD Graphics 3000.

Max Temperature—Half Life 2 Episode 2

The biggest difference I noticed was the max temperature near the exhaust fan(s) on the notebooks. The new 15 is a whole 13C warmer than last year's model.

There's no way to get around it—if you're going to be using these systems to anywhere near their potential, they are going to get significantly warmer than last year's. Also, as a result, the new systems are noisier. Fans are more likely to spin up and given how small they are, they are quite audible. If this is a deal breaker for you, the best advice I can give you is to wait for Ivy Bridge.

Ivy Bridge will bring mild updates to the Sandy Bridge architecture, an increase in performance but more importantly it'll bring Intel's 22nm process. At 22nm I'd expect somewhat lower power usage than what we're seeing here today. Ivy Bridge is expected to ship in the first half of 2012, with updated MacBook Pros arriving ~2 months post introduction.

FaceTime HD Cameras Battery Life
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  • Wolfpup - Friday, March 11, 2011 - link

    Just LOOK at that. Visually it just makes things look worse...looks like it's taking up space for maybe two more cores, or a fifth core and more cache, or something.

    The only good thing about it is it may help AMD get back in the game. Assuming Bulldozer ends up relatively competitive, AMD's going to be able to have more cores or cache in the same die space, or else have a smaller CPU with the same performance.

    Personally I'm a big fan of Intel's rock solid stability, but it feels like AMD gets better and better with that, where they feel like a real competitor now, and I'd love to see them get parity with Intel or even surpass them!

    To people who have called the higher end config's GPU "high end", it's not. It's a decent mid range part. For the price it ought to have better...maybe that on the low end config and an 800 core part on the high end config (or a Geforce GTX 460), but at least it's a big jump up from the last gen models.
  • Belard - Saturday, March 12, 2011 - link

    UH... and what reliability issues are you talking about with AMD? What, intel never screws up? I buy, own and sell both brands.
  • Wardrop - Friday, March 11, 2011 - link

    To be honest, I'm somewhat surprised that Apple don't offer a solution for reducing cable clutter, given their minilast design of the iMac, etc. A docking station sounds like an obvious solution. I'm sure Apple could come up with a really elegant way of docking your Macbook, or otherwise, just connecting all your cables via one main connection.

    I envisage a magnetic solution. You could either have a docking station, where the Macbook sits on something (a stand would be nice). Otherwise, a breakout box type of device, where you plug all your audio, USB and display cables into it, and then attach the breakout box to a single interface on your Macbook, whether it be a plug on the back, the side, or even a magnetised strip on the bottom of the notebook?

    I use my Macbook Pro primary as a desktop. It goes through my desktop KVM, to which my Windows desktop is also connected. I try to avoid unplugging my Macbook from my desk however, simply because it's a hassle. I not only have to unplug the cables, but I have to eject my external time machine drive. One of the most annoying things I find however, is that because the screen resolution on my MBP is significantly lower than my desktop monitor, it often screws up all the windows. I find I need to spend time resizing all my windows for the 13" MBP display, and then have to do the same when I connect it back up to my 24" desktop monitor. When you've got 10+ windows all perfectly arranged to suit your working style, it's a major pain, hence I avoid taking my MBP off the desk.
  • tzhu07 - Sunday, March 13, 2011 - link

    I was thoroughly unhappy with the current offerings for a docking station for my late 2006 macbook pro, and so I decided to go to home depot and build one myself. And I made it super elegant and wirefree. Also helps that my monitor is connected to an arm, keyboard wireless, and also mouse is wireless too.

    http://www.majorindulgence.com/file_exchange_data/...

    ahhhhhhhhhhh.....super clean
  • bronze5420 - Friday, March 11, 2011 - link

    this is definitely the best computer review i have ever read. very informative. answered all the questions i had and then some. keep up to good work. and does anybody know if OSX Lion will feature TRIM support for third party SSD's?
  • 13579abc - Friday, March 11, 2011 - link

    First let me echo the sentiment of gratitude expressed throughout this forum. AnandTech really is a cut above other tech sites.

    Second, if I may add my two cents, heat and noise are such an important part of the mobile experience that they might deserve a little additional attention in this review, particularly given that apple tries to differentiate itself from competitors in these areas. This review touches on the surface temperatures of these new Macbook Pro models, but I wonder if there are any plans to more thoroughly examine surface temperatures in different areas of the notebook (i.e. palm rests, keyboard, bottom surface…). Also, does AnandTech have any comment on the effect of inappropriate quantities of thermal paste reportedly used in the notebooks? Some forum posts report amazing thermal improvements resulting from properly applying new thermal paste, but to be honest I have some doubts regarding the validity of these posts and think that they might be misleading.

    Along similar lines are there any plans for a quantitative analysis of the noise output from these new models.

    Again,thanks for a great review.
  • tipoo - Saturday, March 12, 2011 - link

    Seconded, some numbers on thermals and decibels would be nice.
  • Balfa - Saturday, March 12, 2011 - link

    I've just bought the new 17" that I use mainly for software development but even at 1920x1200 it is a little on the cramped side. So at home I connect it to a Cinema Display 27'' via mini DP cable to the new combo TB-MiniDP port. And the monitor cable use also a Magsafe connector and lastly a usb2 for camera, sound and 3 usb ports at the back of the monitor like most folks already know likely.

    Now what I really wish for the future Apple is extends that paradigm of a monitor-docking station with a new 27'' monitor with only the Magsafe and one Thunderbolt cable. At the back of the monitor implements every ports that could be needed: USB3, FW800 (1600 maybe why not), eSATA (unlikely I know). And lastly add a powerful discrete GPU in the monitor itself with a quick access door to upgrade it if needed. That way you could remove the one in the MBP for lower cost and better battery life and still have a powerful GPU solution at home for gaming, transcoding and the like.

    I think the monitor is the best place for docking a laptop, not needs for a separate device. I already put all my external disks behind it anyways (I place my monitor in the middle of the desk so there's a lot of empty space behind) and it will be the shortest route to plug them, less clutter that way. Gee it's a great idea isn't it!
  • MrBrownSound - Saturday, March 12, 2011 - link

    Once again anandtech pulls off a amazing review. With this information I can cofortably say I will wait for Lion to come out.
  • ProDigit - Saturday, March 12, 2011 - link

    None of these machines is worth their price!
    The 13" has a price of a 16" laptop

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