Battery Life: All Day Computing

AMD makes a point of their mobile offerings (A/C/E-series APUs) all offering “all day computing”, with a note that “all day” is defined as eight hours or more. While that’s easy to do with a gigantic battery, doing so with the typical 48/56Wh batteries in mainstream laptops is a lot more difficult. One of their test notebooks apparently manages around 10.5 hours (best-case) with a 62Wh battery, compared to 6.5 hours for a similar Core i5-2410M laptop. Without specifics on all the settings, we’ll just say that our results for “similar” laptops don’t show nearly the disparity AMD achieved, but the important point is that AMD is finally competitive in battery life.

We ran our usual series of battery life tests, with the LCDs set for ~100 nits (70% brightness for the Llano laptop). We shut off WiFi for the idle test and mute audio; the Internet test is run over WiFi and repeatedly loads four tabs of content every minute, again with audio muted; finally, the H.264 playback result is done with a set of earbuds connected and WiFi disabled. Here’s how the Llano laptop stacks up to some recently reviewed laptops—you can compare Llano with other laptops in Mobile Bench.

Battery Life - Idle

Battery Life - Internet

Battery Life - H.264 Playback

Starting with pure battery life, only three laptops consistently offer longer battery life than the Llano system: the ASUS U41JF, MSI’s X370, and the quad-core Sandy Bridge notebook. Also, the ASUS K53E boasts better battery life in the H.264 playback test, which for whatever reason is a test where SNB has proved particularly potent. Intel’s DXVA decode may be efficient, but it's also possible it's doing less work; we're running the test again with all of AMD's video enhancement features turned off. [Update: I retested with all the AMD video enhancement features disabled, and battery life didn't change, so Intel is simply more efficient at H.264 decoding with SNB.]

Back to the discussion of battery life: all three of the laptops that beat Llano have the advantage of slightly to moderately higher battery capacities, so the comparison isn’t entirely fair. Let’s level the playing field by looking at relative battery life.

Relative Battery Life - Idle

Relative Battery Life - Internet

Relative Battery Life - H.264

Rather amazing is that Llano actually rises to the top of the charts in the Idle test, and it’s only slightly behind the competition in the other two tests. Considering the X370 is equipped with an E-350 APU, the fact that Llano is even close is surprising. While we should note that the X370 wasn’t the most efficient of the E-350 laptops we’ve tested, we also need to point out that the 13.3” LCD is a lot closer to the 14” panel in the Llano notebook than the 11.6” panels used in the Sony YB and HP dm1z. The dual-core SNB notebook still leads in the H.264 test, and considering it has a 15.6” panel we’d say that relative battery life is very similar between the two.

We also want to talk about AMD’s claims of “all day battery life”. If we accept their definition of 8+ hours, the test laptop doesn’t actually hit that mark in our idle test. We did run the same test again at 40% LCD brightness (around 60 nits) and managed eight hours exactly, but that’s in an absolutely best-case test. For Internet surfing, which represents a more useful metric, the best way to get 8+ hours is demonstrated by ASUS’ U41JF: stuff in a higher capacity battery!

Rounding out the battery life discussion, we also tested battery life while looping 3DMark06 at native resolution (1366x768). This represents a reasonable 3D gaming scenario, and Llano still managed a reasonable 161 minutes. Considering graphics performance is a healthy step up from what Intel’s HD 3000 offers and that AMD manages double the battery life under gaming situations compared to the K53E, mobile gaming is clearly a win.

Overall, for the first time in a long time, AMD is able to offer battery life that competes with and even exceeds what Intel offers with their current mainstream offerings. There are of course a bunch of lower power Intel CPUs we could discuss, but looking at the 35W TDP parts the combination of 32nm and power gating has brought AMD back into the discussion. Even more interesting is that you should be able to get something like our test laptop for $600, possibly less, compared to dual-core SNB i5 laptops that start at $700. But then, perhaps Core i5 isn’t the best comparison for quad-core Llano, despite what AMD might like to say? Let’s move on to general performance and gaming discussions before we decide which mobile part is the “best”.

AMD’s Llano Mobile Test Platform Application Performance, Round One: PCMark 7


View All Comments

  • JarredWalton - Tuesday, June 14, 2011 - link

    Civ5 and TWS2 are both tested with the latest drivers. The K53E was also tested with drivers that are at most a couple months old. Intel current lists the latest laptop drivers as from 4/13/2011, which is what I'm running on the Intel units right now. If there are some newer drivers that I'm missing out on, let me know and I'll go try them. Reply
  • duploxxx - Tuesday, June 14, 2011 - link

    Nice review, it seems like there is a lot of work on CF.

    Actually I reviewed the Liano already months ago, I mentioned in the last mobile reviews that it will be better performing then the Toshiba with the P920 with really good battery performance. So it is a win -win for the budget line anyhow. Top line remains intel for the CPU power.

    Regarding the quote:
    Now if you want to have your cake and eat it too, the APU to wait for would be Trinity. Due out somewhere in the 2012 - 2013 timeframe, combine a Bulldozer derived architecture with AMD's next-generation GPU architecture and you've got Trinity.

    Trinity will not only be an improved GPU it also has the BD core inthere which will offer much more punch. THe reason LIano is late is because of the 32NM process. It could have been released much sooner. Sure they took an outdated K10 and that is the main issue together with the not enough aggressive Turbo for single thread, they should have adapted this more aka BD.

    But assumin Trinity is a rather late 2012 project (by stating 2012-2013) you are way way off...
  • ET - Tuesday, June 14, 2011 - link

    Quote probably reflects an increase in pessimism due to recent events. Bulldozer is still not out, and AMD is said to have had a hard time getting clocks up. So sure, we're all hoping to see Trinity early in 2012, but anyone setting their expectations a little farther are less likely to be disappointed. Reply
  • duploxxx - Wednesday, June 15, 2011 - link

    didn't i mentioned it would be launch faster then expected?

    the delay of Zambezi BD has nothing to do with real architecture issues.....
  • ET - Wednesday, June 15, 2011 - link

    That's not the sites which posted on it, including Anandtech, said based on what AMD said (that is, that Bulldozer was not up to speed). Reply
  • Jamahl - Tuesday, June 14, 2011 - link

    Was that really needed? I mean...really? Who the hell would do that and for what reason? Reply
  • ET - Tuesday, June 14, 2011 - link

    I already got my E-350 laptop, but as Jarred says, Brazos just became less interesting. I'll be waiting to see what price point and performance the dual core Llano will have. What impressed me most was battery life, which is competitive with the E-350 laptop, and it'd be interesting to see how small and light Llano laptops will get.

    The other takeaway I have from this is that as usual I'm impressed at how far Intel has gone with its integrated graphics. Sure Llano gives it a good beating, but that's at the expense of a lot more die space. I imagine that Intel will continue to tweak its 3D cores and I can't wait to see how this race will develop.
  • Anosh - Tuesday, June 14, 2011 - link

    What happened to power consumption?!
    Some of us get laptops due to the optimization in the power department over similar desktop parts!
  • JarredWalton - Tuesday, June 14, 2011 - link

    Power = [Battery Capacity] / .98 [efficiency] / ([Battery life in minutes] / 60)

    So if you take the battery life charts, you can determine roughly what the total system power draw is using the above. Or you can look at the "Relative Battery Life" charts and get the same information as Minutes/Wh instead of converting into Watts.
  • jabber - Tuesday, June 14, 2011 - link

    In my work I get a lot of laptops to fix. If there is one game or genre that appears on 80% or more of them its......

    The Sims.

    I also get asked a lot "if I buy this laptop will it play The Sims?"

    Never ever been asked if a laptop will play Crysis or any of the games you use.

    Just saying.

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