Core i5 vs. Core i7 Battery Life

With access to the top-of-the-line Core i7 MacBook Pro, I decided to run comparative battery life tests between it and the entry level Core i5 system. The main difference is a higher clocked CPU and an extra MB of L3 cache. The i7 ends up being up to 15% faster than the i5, but at what detriment to battery life.

The results below echo what I’ve seen in real world usage. You generally lose a little under 10% battery life when you opt for the Core i7 MacBook Pro vs. the entry level Core i5. You do gain more than that in performance, a noticeable increase in my opinion, but if you value battery life more than performance you’re better off with the i5. If you're upgrading from the previous generation, you may actually see a real reduction in battery life depending on your workload if you go to the i7. Update: The Core i7 model we're testing also uses the high res display, which should consume more power than the low res standard display. The difference in battery life isn't just due to the CPUs but the display as well.

Note that your mileage may vary considerably here. Years ago Intel started shipping its processor families with a range of core voltage options. Two 2.66GHz Core i7s may run at wildly different core voltages, which would ultimately impact battery life. It’s possible that I got a particularly bad Core i7 (or particularly good Core i5) and that you’ll see a different gap than I did.

I also ran the i7 system in the rest of our Apple battery life suite.

XviD Video Playback

I ripped The Dark Knight to XviD and played it back continuously in QuickTime X with Perian installed. For this test the display was set to full brightess and audio was set at two bars below maximum. Once more the hard drive was allowed to go to sleep if it was idle. The AirPort (wireless LAN) was enabled and connected to a local access point less than 20 feet away.

XviD playback actually demonstrates our largest improvement in battery life over the previous generation. If you've got a MacBook Pro from just two years ago you'll have roughly twice the battery life with a new one.

Flash Web Browsing

The test here has three Safari windows open, each browsing a set of web pages with between 1 - 4 animated flash ads per page, at the same time. Each page forwards onto the next after about 20 seconds.

As always, the display is set to 50% brightness, audio at two bars, screensaver disabled and the hard drive is allowed to go to sleep if idle. The wireless connection is enabled and connected to a local access point less than 20 feet away.

Heavy flash web browsing is effectively no better on the new MacBook Pro compared to the old one. If you opt for the Core i7, you'll actually take a hit compared to the older MacBook Pro. You might be wondering why we don't have more historical data for our Flash web browsing battery life test. I'm glad you asked...

Battery Life: Better and Worse in the Real World The 64-bit Snow Leopard/Flash Issue & Windows 7 Battery Life
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  • Howard - Saturday, April 24, 2010 - link

    Can't say I'd ever want a glossy screen. Reply
  • vol7ron - Saturday, April 24, 2010 - link

    I don't understand this, I like glossy screens. Everyone else seems to be against them. Of course, I rarely do anything outside. If I did, I'd probably get a removable screen attachment. Reply
  • softdrinkviking - Saturday, April 24, 2010 - link

    i like glossies too, and i don't ever notice any glare.
    i think there is just an assumption that glossy is bad or something, or
    people are convinced that it's a gimmick.
    maybe it is, but i like 'em.
    Reply
  • Grabo - Saturday, April 24, 2010 - link

    Eh? Since it's relatively hard nowadays to find a portable with a matte screen I must conclude that most people are like you, i.e attached to glossy screens.

    I despise them. Most desktop monitors (still) aren't glossy, and thus I see them as painting a more accurate picture. Glossies increase saturation and contrast, something which then is a lie, even though most people absolutely adore it.
    Reply
  • hybrid2d4x4 - Saturday, April 24, 2010 - link

    I've got natural light coming into the living room from ~135deg around me, and the glossy displays on family members' laptops are completely useless in that room- it's all reflections. I'm probably in the minority, but I'd like to be able to use a laptop outdoors (and probably would). There's no way I'm ever gonna settle for glossy, even if it means never buying a laptop. Reply
  • MadMan007 - Saturday, April 24, 2010 - link

    Glossy is fine on a desktop monitor where you can control the environment. On a laptop though? Hells no. Reply
  • orthorim - Monday, April 26, 2010 - link

    I have a 17" glossy. I like sunlight and a view, and working near windows with this laptop is very annoying, way too much reflection. In addition, I don't see how anything looks much better on the glossy screen - possible exception movies which really look fantastic on my screen.

    But this is primarily a work laptop, and as such, it has a major flaw with the glossy screen. When working in Cafes or near a window, I have to crank up brightness all the way to the max, which then reduces battery life.

    I will go with matte again next time. The gains from glossy are minimal, the downside clearly outweighs this. If you never go outside or don't live in a sunny climate, maybe it doesn't matter. I am in the tropics, and I love to see the outside when working.
    Reply
  • iamezza - Sunday, April 25, 2010 - link

    I agree. I don't use a laptop much outdoors, but when I'm indoors there is usually bright light coming in from the windows that can cause a lot of glare. Reply
  • Socratic - Monday, April 26, 2010 - link

    Have to agree with others here. I much prefer a matte screen. If there are any windows in the room the glare at certain times of the day on a glossy screen makes it unusable, at least for me. In an editing room or business environment with no outside lighting, I can see the appeal. I have however seen offices that the glare from the over head fluorescent lighting was so bad that users had to hang something over the top of the monitor on a glossy screen to be able to use it. Reply
  • cjhao - Saturday, April 24, 2010 - link

    'MacBook Pro brought posted some incredible battery life numbers'
    i created an account because you guys are great, so i wanted to help maintain the awesome reputation in my small way by pointing this out
    Reply

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