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
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  • ET - Tuesday, June 14, 2011 - link

    So, what do you tell them? The only benchmarks of The Sims 3 I could find are pretty old and didn't offer much detail, but I think based on them that high quality would require more than the lowest IGP. (Then again, normal or low quality should probably run fine on anything.)
  • msroadkill612 - Tuesday, August 2, 2011 - link

    ta 4 the post - but dont salesmen have a duty to sell them a bit of insurance against the next game fad
  • ash9 - Tuesday, June 14, 2011 - link

    Bring on the OpenCL apps, excuse me applications- Excel rewritten to take advantage of heterogeneous computing would silence everyone about Star CPU cores. The ball is in the hands of the people (to buy them), then the software developers (to program for them) - that's why Star cores? APU apps needed
  • msroadkill612 - Tuesday, August 2, 2011 - link

    I think it will happen. Big mobs will identify niches that can profit from OGPL & profit from using it - open languages always win in the end.

    I see fusion server apuS in the future.
  • FISHRULE - Tuesday, June 14, 2011 - link

    What a terrible CPU, who would want something that performs like a Phenom in a new computer circa 2011. The future might be fusion AMD, but you sure as heck aren't part of the future anymore.
  • jabber - Tuesday, June 14, 2011 - link

    90% of laptop owners wouldnt know if they were using a Brazos or an i5 in their laptops.

    The only real differential is in transcoding, ripping etc. and very few folks in the real world actually do that. Especially on laptops.

    Price is far more important than outright performance. Has been for some time now.
  • RussianSensation - Tuesday, June 14, 2011 - link

    False. My gf doesn't know anything about computers. But she somehow knew that Intel makes the best mobile CPUs even before asking me what to get. Clearly Intel marketing > AMD's. All of my current friends who just bought a computer all went with i3/i5/i7 processors only because they "heard" Sandy Bridge is the fastest CPU around.

    Llano is nothing more than a Phenom with a faster GPU. Phenom already didn't sell well against C2D/C2Q/Core i7 (1st) gen and isn't getting any better against SB. The only way AMD is gaining market share is if they ship cheap laptops with Llano to users for whom the price of a laptop is the most important factor.
  • ET - Tuesday, June 14, 2011 - link

    Well, you have pretty computer literate friends. Most people I know would have no idea what Sandy Bridge is, probably not even what i3 and i5 are, and would only buy i3 or i5 because: a) AMD had very little market presence until now; b) I'd recommend them. That said, most of the people I know have no idea that AMD exists and is making CPU's (I mention it occasionally, and they're always surprised, so I guess it doesn't register), so it does look like AMD's marketing is pretty crappy.

    That said, I think that your analysis of why Llano will fail isn't right. For most people the CPU power really doesn't matter that much. They'd have no idea if i3 or Llano is better, and most likely won't be able to tell the difference in practice (unless they run a game for which the HD 3000 is unsuited). Sure Llano is for the low end market, but that's where most sales are, and it's certainly much improved in terms of power usage, which is an important enough measure to help it gain market share.
  • RussianSensation - Tuesday, June 14, 2011 - link

    You are probably right that most people won't tell the difference between a Llano or an i3/i5/i7. But to them the perception of knowing that they have a slower CPU is what matters. One of my friends was building a PC for browsing the net only. I told him he'd be perfectly fine with a $100 CPU but he insisted that the system must have Sandy Bridge because it's the latest modern CPU. I gave up trying to convince him that his internet browsing experience will be more limited by his ISP latency and speed rather than CPU performance.

    So as long as AMD convinces the average consumer that Llano is at at least as good, they will do well. The problem is AMD's marketing department is worse than a 1st year undergrad student studying marketing in business school. They think if they pay millions of dollars to put AMD on F1 cars, people will notice?

    You made a very important point - a lot of people don't even know what AMD is or that there is another competitor to Intel. Imagine if GM, Ford or Chrysler made cars that were more reliable than Honda or Toyota. It would still be a while until the average consumer would abandon the Japanese brands since the perception of reliability would lag behind reality. AMD has this similar problem with their CPU brands, which only marketing can fix.
  • jrs77 - Tuesday, June 14, 2011 - link

    Really... that's rather unimpressive.

    The GPU of Llano beats intels HD-graphics in games, what a surprise. But how many people do I know personally, that play games on their laptops anyways? Laptops are primarily used as mobile office-computers and they do still rely more on CPU-performance.

    From all the experience I've made the HD3000 graphics of mobile SNB CPUs are perfectly fine for all tasks I throw at them (excluding games). So the question is, why would I buy a Llano-based laptop instead of a SandyBridge one?
    Llano doesn't offer better battery-life so the only reason might be the price, but with i5-2xxx laptops starting at $600 I really don't see alot of competition there for intel, if we're talking anything else then gaming.

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