Gaming Performance

Since this is our first experience with Kepler, we ran the GeForce GT 640M through its paces at each of our presets despite the internal panel of the Acer TimelineU M3 only running at 1366x768. In the process we ran into a bug with Battlefield 3, though, where that game would crash every time we tried to change video settings in-game with a secondary screen connected. As a result we only have Battlefield 3 results at our "Value" preset.

Unfortunately we're also pretty shy on results of notebooks using our current gaming benchmarks, so for now these charts are going to feel a little spare. Thankfully, the most interesting comparison (that between the GTX 560M and the GT 640M) is something we can definitely provide.

Batman: Arkham City - Value

Battlefield 3 - Value

Civilization V - Value

DiRT 3 - Value

Elder Scrolls: Skyrim - Value

Portal 2 - Value

Total War: Shogun 2 - Value

The 640M produces reasonable performance in each game. Given how it's tough to gauge just what clocks the 640M is running at and how little we can reveal about what we know of Kepler, it's difficult to pinpoint exactly what the bottleneck might be. It's entirely possible that at the Value preset is CPU-limited between the ASUS and Acer, while the 6650M in the Sony Vaio Z2 is likely bandwidth limited due to being used on a Thunderbolt connection and thus reduced to PCIe x4 speeds.

Batman: Arkham City - Mainstream

Civilization V - Mainstream

DiRT 3 - Mainstream

Elder Scrolls: Skyrim - Mainstream

Portal 2 - Mainstream

Total War: Shogun 2 - Mainstream

I'll take it as a point of pride that NVIDIA uses almost all of our benchmarks in their reviewer's guide, but what's interesting is that all of our results here are actually a touch higher than what we were told to expect. At 1600x900 the GT 640M is undoubtedly feeling the pinch from the 128-bit DDR3 memory bus, but it still holds its own. This is about the highest resolution you could conceivably want to run this GPU at, at least without GDDR5 (which the 640M does support).

Batman: Arkham City - Enthusiast

Civilization V - Enthusiast

DiRT 3 - Enthusiast

Portal 2 - Enthusiast

Total War: Shogun 2 - Enthusiast

I've never seen a GPU with a 128-bit memory bus and DDR3 memory acquit itself particularly well at 1080p, and NVIDIA isn't about to change that with the GT 640M in the Acer TimelineU. At this point the chip's limited memory bandwidth is just plain overwhelmed and can't keep up, shader power be damned.

With all that information now on the table, it's reasonable to say the GT 640M is definitely a powerful GPU and certainly a step forward from the Fermi-based GT 540M. At 768p, even a DDR3-equipped 640M is undoubtedly going to provide the excellent gaming experience that NVIDIA promises, but anywhere beyond that is still going to require more memory bandwidth, full stop. There's only so much one can do with the die before having to make that concession, and I feel like the 640M needs GDDR5 to really shine.

Application and Futuremark Performance Battery, Heat, and Screen Performance
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  • tipoo - Wednesday, March 14, 2012 - link

    It has 192, yeah. Interesting. But its in the same thermal envelope so who cares how many shaders there are, maybe they went AMDs route with less powerful individually but more numerous shaders.
  • extide - Wednesday, March 14, 2012 - link

    It pretty clear that the CUDA cores in kepler cannot be directly compared to the ones in past generations.
    With the full GK104 being rumored to have 1536 yet nowhere near 3x as fast as a GTX580 (512 CUDA cores), plus this card with 384 and significantly less performance than the 192 based fermi card.
  • MarsMSJ - Wednesday, March 14, 2012 - link



    The mention of the 6650M in the Sony notebook should warrant an asterisk on all the GPU performance graphs. In those graphs there is nothing to differentiate or tell a reader that a built in 6650M will perform much better than a 6650M. We all know those graphs will be referenced and they imply that 6650M in a standard or non standard implementation will work

    I can see clearly why NVidia likes your graphs because they're misleading.
  • mamisano - Wednesday, March 14, 2012 - link

    I totally agree and glad that someone else feels the same way as me.
  • JarredWalton - Wednesday, March 14, 2012 - link

    The text has an explanation for the poor performance of the 6650M, and actually I have a 6630M review coming shortly where it outperforms the 6650M results, but there's still a large gap between it and the GT 640M.

    The bigger issue is that AMD doesn't have a lot of compelling laptops using their GPUs, and even the ones that do go with AMD have other quirks. The Z2 has it in an external dock where performance (at least on the internal laptop display) is hindered by Thunderbolt bandwidth; the VAIO SE16 (which I'm reviewing right now) has the 6630M, but the manually switchable graphics and almost complete lack of driver updates is going to make it a tough sell for gamers. HP's Envy has the same problem with driver updates.

    We've heard from AMD that they'll be rolling out a "unified driver" for all their switchable graphics laptops, but until (if) that happens you're basically asking for problems down the road. Optimus may not be perfect, but compared to the AMD alternative it sure feels like it. :-(
  • MarsMSJ - Wednesday, March 14, 2012 - link

    I understand what you're saying about your options. However, that still doesn't address the fact that your graphs do not express this is an exotic GPU implementation with additional contraints that are not normal, driver quirks or not. Keep mind you have lots of graphs and a very important bit of information hidden half way between them.

    You're not new to the internet, you know the nature and power of these graphs and their interpretation on the web. I'm not surprised in the least bit NVidia loves your graphs and testing.

    Anyway.... any indication about the heat from this NVidia mobile GPU being common thing with upcoming products? :)
  • Hulk - Wednesday, March 14, 2012 - link

    with the Super PLS screen.

    Help us Dustin Sklavos Kenobi, you're our only hope!
  • kenyee - Wednesday, March 14, 2012 - link

    They should have stuck at least a 1080p screen on it and 4 memory slots so you can stuff 16GB of memory in it :-P

    I'm hoping the Macbook Air shows them how it's done too...and I hate rooting for Apple :-P
    Sony's Z2 looks great, but has the same memory limitations, and no Kepler GPU :-(
  • trajan2448 - Wednesday, March 14, 2012 - link

    I travel quite a bit and I always watch movies with my laptop. I hope they keep the DVD drive until there is some equivalent no hassle solution.
  • noeldillabough - Wednesday, March 14, 2012 - link

    Honestly say I haven't used an optical drive on laptops for years. Rip the movies to DivX or XVid and watch em on whatever device you like.

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