Last week I reviewed the new MacBook Pro. Not so much reviewed as tested battery life on it. I came away impressed. In three tests I managed to get between 5 and 8 hours of battery life out of the new 15” notebook. That’s longer than anything else at this performance/size level in my lab right now.

The previous generation MacBook Pro was good for about 3 - 5 hours. The less you do, the more you’ll find yourself closer to that 5 hour maximum. The more you do, the more you’ll find yourself at around 3 hours. Makes sense, no?

The new MacBook Pro works the same way. If you’re just typing in a window most of the time then you’ll find the new model, with integrated battery, will give you a crapton of battery life. Even using it like a productive, multitasking machine will yield close to 5 hours. Obviously your mileage may vary, but with 46% more battery capacity than the previous generation MacBook Pro you can expect at least that in battery life improvement from the new one.

A while ago, at the end of another MacBook review, I pointed out something odd. Battery life under OS X was much, much better than battery life under Vista:

  Wireless Internet Browsing DVD Playback Heavy Usage
MacBook Air (OS X) 4.98 hours 3.93 hours 2.7 hours
MacBook Air (Vista) 2.55 hours 2.05 hours 1.75 hours
Lenovo X300 (Vista) 2.82 hours 2.18 hours 1.68 hours


I attempted to create the same tests under Vista as I did under OS X and consistently found that the Mac notebooks offered much better battery life under OS X.

A few people asked how the new MacBook Pro fared under Windows. It lasted up to 8 hours under OS X, but how bad is the hit when going to Vista?

To find out I put together the same test I ran under OS X under a fresh install of Windows Vista x64 SP1. I even used Safari and iTunes for 64-bit Windows to keep the applications as similar as possible between the OSes.

I set Vista to the same brightness and power settings as OS X. I even chose the maximum power saving profile under Vista (my earlier tests used the Balanced profile). I ran the same wireless web browsing test I did for the new MacBook Pro review:

The wireless web browsing test uses the 802.11n connection to browse a series of 20 web pages varying in size, spending 20 seconds on each page (I timed how long it takes me to read a page on Digg and came up with 36 seconds; I standardized on 20 seconds for the test to make things a little more stressful). The test continues to loop all while playing MP3s in iTunes.
I only ran that test since it should give a good idea of the type of battery life degradation we can expect when going from OS X to Vista. If enough people would like to see more, I can always look at running a few more numbers but I believe this test alone should sum things up quite nicely.

Under OS X, this test yielded a battery life of 8.13 hours. The same test under 64-bit Windows Vista? Just over 6 hours:

New 15-inch MacBook Pro (73WHr battery) OS X 10.5.7 Windows Vista x64 SP1 Windows 7 RC1
Wireless Web Browsing (No Flash) Battery Life 8.13 hours 6.02 hours 5.48 hours


That’s nearly a 26% drop in battery life from OS X to Vista. When I first published these tests I spoke to a few PC OEMs to see if they had noticed any similar results. No one was willing to go on record but some OEMs did at least admit to seeing a ~20% difference between battery life in OS X and Vista.

The situation is apparently a bit better under Windows XP but not significantly. Even more depressing is the fact that Windows 7 doesn’t appear to make the situation any better. I still have a couple more hours in my Windows 7 run but I’ll update this page once I have the results. Right now it’s looking like ~6 hours for the new MacBook Pro under Windows 7 x64 RC1. Update: I finished the Windows 7 results and unfortunately it looks even worse than Vista. The even lower battery life is possibly due to earlier, unoptimized drivers for Windows 7. Either way, it doesn't look like Windows 7 is going to fix this issue.

Many have said that Sony and Lenovo are capable of offering similar battery life under Vista to what Apple can provide under OS X. We’ve been after both companies to get us hardware to help prove this point, but so far neither one has actually followed through. Needless to say, this is something we’re going to continue to investigate. I just figured you all might like to see updated results.

The SATA 3Gbps vs. 1.5Gbps Issue


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  • Narcofis - Tuesday, June 16, 2009 - link

    In an earlier article you mentionned optimization with the System Managment Controller chip that helps the battery life. I wonder if OS X turns it on and off when it starts.

    Just wondering.

  • thorgal73 - Tuesday, June 16, 2009 - link

    I remember OCZ slowing down its Mac version of the Vertex drive, so went to look up a news post about it :">

    On the other hand I'd still like to know which mobile chipsets do offer speeds higher than SATA150, in practice. Here's a post about that :">

    Maybe you guys can figure this out ?
  • pmonti80 - Tuesday, June 16, 2009 - link

    Acer Aspire Timeline series is also capable of delivering "8 hours" of battery life at a low price. It's a CULV notebook, but it is quite interesting if you need so much battery life. Reply
  • abs0lut3 - Tuesday, June 16, 2009 - link

    Hi Anand,

    Would it be possible if the reason OS X has longer battery life compared to Vista was because of Apple "capped" the HD bandwith through software at 1.5Gb/s while Vista and Windows 7 are both running at 3.0Gb/s?
  • unfalliblekrutch - Tuesday, June 16, 2009 - link

    Perhaps there are legal issues with doing this, but for curiousity's sake, perhaps installing OSX on a "windows" notebook and testing to see if that causes it to have a longer battery life than running windows will determine if OSX uses less power or if OSX has hardware specific trickery going on to make the battery last longer. Reply
  • Methodical - Monday, June 15, 2009 - link

    Stupid thought, but have you considered, almost just for giggles, running your battery bench in a VM'ed copy of windows?

    Most likely the battery life will be even lower..... but there's an ever so slight chance that os x is doing something tricky under the hood, and if so your battery life could increase. Even staying the same could be an indicator, with the VM overhead and such.
  • gcor - Monday, June 15, 2009 - link

    One reason Vista MAY have a shorter battery life is Microsoft's business model of backward compatibility. As I understand it, in order for MS to support the multitude of old software on it's new operating systems, MS codes and tests specifically for legacy applications. For example, if you want to run the original SIMS on Vista, the OS detects that SIMS is running and performs code specifically so that SIMS works.

    The need for specific handling is two fold. The original OS function calls may not have behaved exactly as per the spec, so application developers coded for the actual behaviour provided by the OS. On the flip side, application developers may have developed code that functioned correctly, but were misusing the intended purpose of the OS function calls.

    I remember reading that when Vista development was running late, that over 95% of the Vista code base was dedicated to supporting backward compatibility and that it was the biggest cause for delivery delay and restriction of functionality.

    If my understanding is correct, then for any given call to the OS, a number of checks are being run for legacy software even when running current applications. This is a backward compatibility tax that we all pay, all the time. With every new release of MS operating system, this problem gets bigger and more complex, requiring more resources at design, code, test and run time. This MAY explain why battery life has reduced in Windows 7 more than Vista, which is intern worse than XP.

    Apple reduces these problems in two ways. Firstly, they occasionally break backward compatibility support (e.g. OS-9 to OS-X in 2002). Also, their licensing and testing model for third party applications reduces the amount of "bad but functioning" applications that misuse the OS function calls.

    Mind you, I'm not criticising MS for their backward compatibility support. It's what consumers and business have demanded from them and has made them very successful. It's just that the backward compatibility support back to DOS days has a cost for all of us, including MS.
  • CompOne - Tuesday, June 16, 2009 - link

    Among the many flaws of Vista, and a major reason it was never widely adopted, is the fact that it wasn't backward compatible. I did buy a Vista laptop, but when fewer than half my applications would run on it, I returned it and bought an XP system. Try not making excuses for Micro$oft. They're a multi-billion dollar big boy and can defend themselves. When Micro$oft releases their new buggier, incompatible, operating systems we should instead ask 1)What does this offer thats worth the upfront cost, the time to install it, the time to install all my applications, 2) the cost to replace all my expensive applications that no longer work, 3) the time to find, purchase, and install all the applications that no longer work, 3) the time to learn yet another buggy and unintuitive interface, 4) the cost of new hardware and lower productiviity due to the poorer performance of the bloated and underperforming OS. 5) Does this OS perform the basic functions of an OS well such as disk storage management - Micro$oft has yet to get Windows explorer to work well.

    The conclusion is that Micro$oft is not backward compatible, and their self-serving goal of making money hand over fist clashes with my desire for value for my money.
  • gcor - Wednesday, June 17, 2009 - link

    Interesting you think I'm defending MS. I'm not an MS fan. Far from it. In fact, after working as a developer for 20 years, MS was one of the big reasons I recently threw in the towel and have jumped ship into a brand new career, starting with 4 years back in University.

    However, about Vista backwards compatibility... I'm not surprised not everything worked for you. On the whole, I imagine MS got quite a lot of things to work, but frankly they don't have a chance of getting all the 3rd party apps AND hardware combinations to work all the time. The permutations and combinations of the problem they are trying to solve is patently ridiculous beyond belief. Trying to get it to work is just silly and believing they can do it is gullible.

    Having worked as a master engineer developing telecoms network software for the major firm in the indudtry for over 7 years, I've seen the rod built for it's back by one company where that company controlled every application and every hardware release. In addition, the required quality of all the releases was far beyond a consumer ALT-CTRL-DEL OS like Windows. The problems we had with backward compatibility were enormous. I think MS has NO chance, they don't control all the parts and don't have access to majority of application code or hardware designs. Frankly I think it's futile, BUT, we all expect it of them and they keep promising it.
  • PhreePhly - Tuesday, June 16, 2009 - link

    What software didn't work? Pretty much everything I had running on XP ran in Vista. I say pretty much, because, while I can't think of a single program that didn't run, it's been over 2 years since I installed Vista.

    I don't run Industrial CADD/CAM software, so that might be it, but those programs were always problematic with an OS change. They are typically certified on a specific hardware/software combo. Other than that, Vista was (I run Win 7 RC at the moment) amazingly backwards compatible as well as stable. After SP1, even better. The "Vista is teh suxor" FUD is getting real old now.


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