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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  • Penti - Sunday, April 25, 2010 - link

    There is still no IPS-panels for notebooks being produced really even though the battery powered iPad got one in a area where there were none, but on the other hand as they try to sell it as a machine that can do anything they need a wide-angle viewing screen. Otherwise people would just laugh at it as a ebook-reader and cool colors and comics won't change that. People have grown used to sitting straight in front of the laptop screen. It just isn't acceptable in a tablet device, and smart phones has even begun using AMOLED screens. In fact the professional tablets (i.e. those costing 1500+ dollars) have been using IPS based screens for a while now. But I don't think a single screen is manufactured for 15" notebooks with IPS, and the screens for the 12-13" convertible tablets are optimized for power consumption and viewing angles any way not color. I don't see Apple pony up for IPS-panels in the macbooks. They will get them when the others do use them. Custom parts just aren't apart of their computer lineup. We can't expect more then the Geforce 320M chipset in that apartment :)
  • rcocchiararo - Sunday, April 25, 2010 - link

    Are there diferent "grades" in TN panels quality ?

    im 100% sure my GF notebook has worse viewing angles than my late 2008 macbook pro, and that my 2007 or so macbook white was similar or worse than my gf notebook.

    Also, no notebook from work has a decent display either.

    I almost thought that my macbook pro had a "mobile version" of the s-ips panel my 20.1 inches dell from 2007 has :P
  • rpottol - Tuesday, April 27, 2010 - link

    Yup, Levanto dropped them from Thinkpads because the just could not get them reliably in the quantities they needed.


    I think I will stick with older thinkpads, but then I'm the sort of person who would want a 15" QXGA display (2048x1536) and yet not have the CPU for HD playback (well, perhaps).
  • Xyp - Monday, April 26, 2010 - link

    Anand -

    There is lots of interest in seeing some of your benchmark numbers on the current-gen MBPs (128, 256, and 512...), especially after degradation. If any of your people know the skinny on whether Apple has at all revised the firmware on the currently-shipping Toshiba drives, or whether they will be attempting a TRIM-like function (let's be serious, it's Apple... they'll rename it) with updates to OSX, that information would also be much appreciated.

    Thanks for your excellent site.
  • Wolfpup - Monday, April 26, 2010 - link

    Does this let you install the normal Nvidia reference drivers under Windows? People seem to think Apple's preventing it (or possibly it won't work because of their switching technology).

    Either way, if this won't run normal drivers, that rules it out for me :(
  • asiafish - Monday, April 26, 2010 - link

    I just got the new 15" i7 with high-res matte display, and must say this is by far the fastest computer I have ever owned. Build-quality is every bit as good as my Oct 08 MacBook Air, and far better than any pre-unibody Mac (or any other laptop) I've ever used.

    Battery life is incredible with simple browsing in Safari and email/calendar in Entourage.
  • gochichi - Tuesday, April 27, 2010 - link

    For example, does the glossy high resolution screen offer up the same backlight? How do you know that the $50 cheaper glossy display will have the 400 nits backlight? Is the 1440x900 screen as bright?

    I mean guys, what I'm hoping a tech website can do for me just to put it bluntly is help me make a decision as to which product to use or buy. In a nutshell, help me make an informed decision. What I want to see is a 3-way comparison of the standard glass covered display, the glossy high res display and the matte high res display. What I get instead is an opinion that someone else would go with a glossy high res display that they've in fact never even seen.

    Measure stuff for me, show me some pictures of things I want to see. I've been a long term reader of Anandtech and frankly I expect the obvious. Worse yet, I can go to a local Apple shop and compare th low res to the matte display for myself.

    Honestly... on what grounds are you recommending the glossy high res. It just "sounds cool"? Sigh.
  • Brian Klug - Friday, May 14, 2010 - link

    I think you're reading a different article entirely, because basically everything you just sounded off on is actually in this one:

    1. 400 nits claim - Right inside:

    Performance was 412 measured with an i1D2.

    2. Matte > Glossy - Also inside:

    Comparison and side-by-side with photos.

    I'm confused what you're reading, because *all* of that stuff is there.

  • jlyall - Saturday, May 1, 2010 - link

    Hi Anand,

    A big cheers for both the write ups on the new MBP. You have made my job of choosing about 1000x times easier. The hole in my pocket will be bigger but I know I will be happier in the long run. Cheers again and have a lovely day.

    warmest regards,

  • Woodoo - Tuesday, May 4, 2010 - link

    Hi there, I have a question regarding viewing angles differences between the glossy and matte options. Is there a noticable (or at least some) difference between the two LCD panels mounted to the latest MacBook Pros in this aspect?
    P.S.: I'd love to see an IPS panel in the future MacBooks Pro, even as a high price option...

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