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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  • sinigami - Tuesday, June 14, 2011 - link

    these prices, are definitively NOT in the netbook range:

    $500 - thinkpad x120e
    $550 - HP Pavilion dm1
    $600 - sony vaio YB

    who the hell would pay that much dough for Atom level performance?
  • sinigami - Tuesday, June 14, 2011 - link

    even AMD's slower 1.0GHz C-50, costs more than the Atom in the SAME MODEL netbook (while benchmarking slower than the atom!):

    $250 - Acer Aspire One 255 with the FASTER Intel Atom
    $330 - Acer Aspire One 522 with the SLOWER AMD C-50
  • ET - Wednesday, June 15, 2011 - link

    First of all, the (lowest) prices I found at were $250 for the 255 and $310 for the 522, which is a smaller margin.

    Acer 522 has a 720p display vs. the 255's 1024x600. That alone is worth a significant price difference. It also has a HDMI port and a CPU (APU) that can play 1080p HD videos (or 720p on the internal display). The 255 is worth crap for video playback, a very common laptop use these days.

    The C-50 can also play some games. Sure, older ones and at low settings, but it's something the 255 simply can't do.

    In terms of general performance, the C-50 should be competitive with the Atom when it comes to web browsing and word processing.

    In short, the 522 is so much better than the 255 that a $60 premium is really not a lot.
  • sinigami - Wednesday, June 15, 2011 - link

    "But, but, the 522 has an HDMI port on it!".

    Personally, i wouldn't pay $80 more for a netbook that is even SLOWER than an atom, no matter how much lipstick they put on that pig -- i mean, no matter how many hdmi ports they stick on that snail.

    And they could stick whatever size screen they want on it, and i'm sure they would charge a whole lot more if they put a 55" on it, but i'd surely NOT buy it with a C-50 in it....

    more bluntly: Acer could put a 1080p display on it, add USB 3.0, give it an amazing sound system, etc, and then charge $1000, but who wants a Ferrari with a Yugo engine?
  • ET - Thursday, June 16, 2011 - link

    Forget the C-50 vs. Atom. Would you pay more for an Atom netbook if it had a higher resolution screen? If not, then fine, but I'm sure many people would. 1024x600 is too low for comfort.

    From your post it looks like you're just trolling, since you stick to "$80 more" even though it's $60 in reality, ignore any comfort from higher resolution and continue to insist that the C-50 is "SLOWER" in caps even though it would beat the Atom in the 255 on SunSpider and probably other benchmarks of real world usability. So I think the prudent thing to do would be to refrain from replying to you, and I will try to do that in the future.
  • sinigami - Thursday, June 16, 2011 - link

    Sorry mate, i'm just slow, not a troll... though it's easy to confuse dain bramage with trolling.

    When i looked at amazon i saw their black one was "Currently unavailable", and the colored ones were $330. I didn't spot the black BZ465 that IS available for $310, so i cede to you that it is only a $60 difference.

    My apologies.

    "Forget the C-50 vs. Atom. Would you pay more for an Atom netbook if it had a higher resolution screen? If not, then fine, but I'm sure many people would."

    That is a reasonable point. $60 is worth it to many people for a better netbooking experience. There is a LOT of value in a highly portable 10" netbook, with hours and hours of battery life, that you can toss anywhere (even a purse), and it does it's intended job of surfing and playing video (not 1080p, of course, but why would it, it has a freaking tiny screen), with a real keyboard and trackpad (and USB ports - take that, ipad). And with a dirt-cheap price, it's all smiles for "many people".

    BTW, i did pay more, lol, except i had to go for an 11.6" screen (@1366x768), even though it isn't as tossable.... i also sprang more for an ultra-low-voltage, dual-core, U/SU chip, so i can have a little more fun, wasting hours on boxcar2d!
  • ET - Wednesday, June 15, 2011 - link

    Where did you get these prices? The HP is $450 (3GB RAM, 320GB disk). The Lenovo is normally $440 for the E-350 version (though currently backordered). It's not rare to be able to get them for less.

    This is still more than netbooks, but it's for a better spec and better performance.
  • sinigami - Thursday, June 16, 2011 - link

    (sorry, i admit my prices were not current, the price has gone down and i haven't kept track)

    still, that is getting very close to the price range where you can get a much better spec, and way, WAY better performance.

    the performance that becomes available, for a few dollars more, first jumps to twice that of an Atom or Zacate, and then you get to the budget i3's, which are, at the least, FOUR times as powerful as an atom or E-350.
  • sinigami - Tuesday, June 14, 2011 - link

    i fully appreciate netbooks for what they are, and i know better than to do anything more demanding than play my 720p MKV anime on a netbook (yes, even the latest Atom machines can do this).

    I'm just pointing out that, currently, with the Brazos and Zacate Fusion APUs, AMD is NOT hitting the price/performance spot that i expected them to.

    the Zacate 1.6GHz E-350, should be priced the same as the Atom machines, up to the price of the Atom/Ion machines.

    i was hoping for AMD's tradition of price/performance to continue, and that would have meant beating or at least NOT being more expensive than Intel!

    and the C-50 is even worse!
  • iwod - Tuesday, June 14, 2011 - link

    I was wondering if they used the latest drivers from Intel, which offer some performance increase. And on the notes of Drivers, GPU drivers these days matter a lot more then Hardware. And ATI has had YEARS of Hard Work on their drivers. While Intel is working hard now, although in terms of catch up they are rather slow.

    Which brings the questions, If Intel really did improve their drivers and bring extra 10 - 20% increase. The Liano doesn't look that attractive at all.

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