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High Detail Gaming and Asymmetrical CrossFire Misfire

Update, 8/10/2011: Just to let you know, AMD managed to get me a new BIOS to address some of the rendering issues I experienced with CrossFire. As you'll read below, I had problems in several titles, and I still take exception with the "DX10/11 only" approach. I can name dozens of good games out there that are DX9-only that released in the past year. Anyway, the updated BIOS has at least addressed the rendering errors I noticed, so retail Asymmetrical CrossFire laptops should do better. With that disclaimer out of the way, here's my initial experience from two months back.

So far, the story for Llano and gaming has been quite good. The notebook we received comes with the 6620G fGPU along with a 6630M dGPU, though, and AMD has enabled Asymmetrical CrossFire...sort of. The results for ACF in 3DMarks were interesting if only academic, so now we're going to look at how Llano performs with ACF enabled and running at our High detail settings (using an external LCD).

Just a warning before we get to the charts: this is preproduction hardware, and AMD informed us (post-review) that they stopped worrying about fixing BIOS issues on this particular laptop because it isn't going to see production. AMD sent us an updated driver late last week that was supposed to address some of the CrossFire issues, but in our experience it didn’t help and actually hurt in a few titles. Given that the heart of the problem is in the current BIOS, that might also explain why Turbo Core doesn't seem to be working as well as we would expect.

AMD also notes that the current ACF implementation only works on DX10/11 games, and at present that's their plan going forwards as the majority of software vendors state they will be moving to DX10/11. While the future might be a DX10/11 world, the fact is that many recent titles are still DX9 only. Even at our "High" settings, five of our ten titles are tested in DX9 mode (DiRT 2, L4D2, Mafia II, Mass Effect 2, and StarCraft II—lots of twos in there, I know!), so they shouldn't show any improvement...and they don't. Of those five titles, four don't have any support for DX10/11 (DiRT 2 being the exception), and even very recent, high-profile games are still shipping in DX9 form (e.g. Crysis 2, though a DX11 patch is still in the works).  Not showing an improvement is one thing, but as we'll see in a moment, enabling CrossFire mode actually reduces performance by 10-15% relative to the dGPU. That's the bad news. The good news is that the other half of the games show moderate performance increases over the dGPU.

If that doesn't make the situation patently clear, CrossFire on our test unit is largely not in what we consider a working state. With that out of the way, here are the results we did managed to cobble together:

Battlefield: Bad Company 2

Civilization V

DiRT 2

Left 4 Dead 2

Mafia II

Mass Effect 2

Metro 2033

STALKER: Call of Pripyat

StarCraft II: Wings of Liberty

Total War: Shogun 2

Given this is preproduction hardware that won't see a store shelf, the above results are almost meaningless. If ACF can provide at least a 30% increase on average, like what we see in TWS2, it could be useful. If it can't do at least 30%, it seems like switchable graphics with an HD 6730M would be less problematic and provide better performance. The only takeaway we have right now is that ACF is largely not working on this particular unit. Shipping hardware and drivers should be better (they could hardly be worse), but let's just do a quick discussion of the results.

If we just look at games with DX10/11 enabled, the story isn't too bad. Not accounting for the rendering issues noted below, ACF is able to boost performance by an average of 24% over the dGPU at our High settings. We didn’t include the Low and Medium results for ACF on the previous page for what should be obvious reasons, but if the results at our High settings are less than stellar, Low and Medium settings are even less impressive. Trimming our list of titles to three games (we tested TWS2 and STALKER in DX9 mode at our Low and Medium settings), ACF manages to average a 1% performance increase over the dGPU at Low and a 14% increase at Medium, but Civ5 still had to contend with rendering errors and Metro 2033 showed reduced performance.

In terms of rendering quality, ACF is very buggy on the test system; the default BIOS settings initially resulted in corrupted output for most games and 3D apps, but even with the correct settings we still encountered plenty of rendering errors. Civilization V only had one GPU rendering everything properly while units were missing on the other GPU, so you’d get a flicker every other frame with units appearing/disappearing. At higher detail settings, the corruption was even more severe. STALKER: Call of Pripyat and Total War: Shogun 2 also had rendering errors/flickering at higher quality settings. Since we didn't enable DX10/11 until our High defaults, right when ACF is supposed to start helping is where we encountered rendering issues.

Just to be clear: none of this means that Asymmetrical CrossFire is a bad idea; it just needs a lot more work on the drivers and BIOS. If/when we get a retail notebook that includes Asymmetrical CrossFire support, we’ll be sure to revisit the topic. Why ACF isn’t supported in DX9 is still a looming question, and AMD’s drivers need a much better interface for managing switchable graphics profiles. A list of all supported games with a central location to change all the settings would be a huge step up from the current UI, and users need the ability to enable/disable CrossFire support on a per-game basis if AMD wants anyone to actually use ACF. We also hope AMD rethinks their “only for DX10/DX11 modes” stance; CrossFire has worked with numerous DX9 games in the past, and what we’d like to see is ACF with the same list of supported games as regular CrossFire. If nothing else, having ACF enabled shouldn't reduce performance in DX9 titles.

In summary: we don't know if ACF will really help that much. We tested Asymmetrical CrossFire on what is, at best, beta hardware and drivers, and it didn't work very well. We want it to work, and the potential is certainly there, but we'll need to wait for a better test platform. To be continued....

Fusion GPU Takes on Gaming AMD’s Llano Platform: Contending for your Mobile Dollar
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  • duploxxx - Sunday, June 19, 2011 - link

    talking about crap??? men you are good at that, as if you need a 2600K for some compiling and add a 6990 to an e-350.

    men you do know someting about computers :) your a joke
    Reply
  • BushLin - Wednesday, June 22, 2011 - link

    If you're going to accuse someone of talking crap (correctly or otherwise) it helps if you know the difference between you're and your when attempting to insult them. Reply
  • Broheim - Monday, June 27, 2011 - link

    I use a fast CPU for compiling because I actually like being productive rather than just staring at the screen.

    my point about the 6990 was that a faster GPU != a better user experience for the vast majority of users, but logic seems to be lost on you.
    Reply
  • Regenweald - Tuesday, June 14, 2011 - link

    I'm currently playing the Witcher extended with a 2Ghz X2 ,a 4670 and 800 Mhz memory on a desktop with no complaints. In game settings medium and high. Are you saying that 2 more tweaked 32nm cores, 80 more shaders and ddr3 1600 or 1800 memory will not offer a good mobile gaming experience ? please. Reply
  • jollyjugg - Wednesday, June 15, 2011 - link

    What kind of super computing application are you going to do in your laptop that you would need that "tremendous CPU power" that you are talking about. As somebody who has used both intel and amd machines for years I can tell you that for most user applications, you will hardly notice any difference in performance. The main complaint was that AMD machines were running hot particularly after intel cameup with power gating in nehalem in 2008. With this part you get a machine that runs way way cooler and almost 150- 200 bucks cheaper than comparable intel machines plus you get discrete quality graphics for free. Nobody can change cynics like you. Because you cant expect Intel to sell anything cheap you would want to AMD to sell things cheaper. Well if you want good things in life you should be prepared to pay. Dont write trash. Like gaming is not important for average user, tremendous computing power and 3 GHz CPU speed is also not important for the average PC user. But multimedia and movie rendering etc is. So go Llano!!! Reply
  • Seikent - Tuesday, June 14, 2011 - link

    This platform offer some good things, but if the prices aren't low it won't go well. Now it's quite easy to find a sandy bridge notebook with discrete gpu for a few more dollars.

    If ACF does achieve to work like CF in the future, it would be great!
    Reply
  • SteelCity1981 - Tuesday, June 14, 2011 - link

    Finally we have an intergrated graphics solution that's worth really talking about. Reply
  • aegisofrime - Tuesday, June 14, 2011 - link

    Judging by the performance, this part won't be priced very high. And that's a worry, considering that it packs 1.45 billion transistors. In comparison, Sandy Bridge is 995 million transistors, and sells for more money. Profit margins are gonna be tight on this one. Reply
  • JarredWalton - Tuesday, June 14, 2011 - link

    AMD has a slide that points out that compared to their previous generation, they're packing a 66 mm2 Northbridge, 200 mm2 CPU, and 1080 mm2 dGPU into a 228 mm2 package. They've made money this past quarter, so this should do better than Athlon/Phenom II. Reply
  • JarredWalton - Tuesday, June 14, 2011 - link

    Note: that's supposed to be 108 mm2 GPU, not 1080. Whoops. Reply

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