Asymmetric CrossFire

Asymmetric CrossFire is supported by desktop Llano APUs. You can combine your A6 or A8 with a Radeon HD 6450, 6570 or 6670 and have both GPUs work in tandem. There are some limitations as we found - mainly asymmetric CF only works in DX10 or DX11 games. While DirectX 9 titles will still function, performance will be suboptimal as you'll soon see.

AMD Radeon Dual Graphics Branding
Discrete GPU 6550D 6530D
HD 6670 HD 6690D2 HD 6690D2
HD 6570 HD 6630D2 HD 6610D2
HD 6450 HD 6550D2 HD 6550D2

Getting asymmetric CrossFire working was a breeze. ASRock's BIOS was setup by default to allow for a secondary discrete GPU to function in dual-graphics mode, all I had to do was install a Radeon HD 6570. My monitor remained plugged into the motherboard and the driver handled the rest:

If you're running a DX10/DX11 game you can get positive scaling, however the gains vary. In Crysis we saw a 68% increase in performance over the APU alone, but only a 12% increase over the discrete GPU by itself:

Crysis: Warhead

HAWX showed us bigger gains on both sides. We saw a more than 2x improvement over the APU alone and a 32% increase over the Radeon HD 6570 by itself:

HAWX

Fire up a DX9 game (or a DX10/11 game in DX9 mode) however, and the results are disappointing. You actually get lower performance than if you had stuck with the discrete GPU alone:

Metro 2033

DiRT 2

Mass Effect 2

StarCraft II

GPU Performance Performance in Older Games
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  • silverblue - Thursday, June 30, 2011 - link

    So, in other words, you completely skipped over what I posted, especially the comparisons between similarly clocked parts? In that case, you may not recall my saying that comparing to Thuban was unfairly skewed in AMD's favour and that for productivity you'd have to be mad to fork out for a high-end Core 2 Quad that is soundly beaten by Thuban under those very circumstances.

    I'm not going to spend anymore time on this subject for fear it may cause my brain to dissolve.
    Reply
  • silverblue - Thursday, June 30, 2011 - link

    We really don't know how Bulldozer will perform. Superior in some areas, inferior in others, perhaps. Its roots are in the server domain so it probably won't be the be-all-and-end-all of desktop performance. Should handily thrash Phenom II though.

    That is, if they stop pushing it backwards... if they do it anymore we may as well wait for Enhanced Bulldozer. :/ I can only truly see Bulldozer being a 9-12 month stop gap before that appears, and as we know, Trinity is going to use the Enhanced cores instead of first generation Bulldozer cores, so it remains to be seen how long a shelf life the product will have.
    Reply
  • duploxxx - Thursday, June 30, 2011 - link

    Ivy Bridge before buldozer, oh man you really have no idea about roadmaps...
    Server and desktop will be there long time before Ivy, if they don't hurry with Ivy even Trinity will be ready to be launched.
    Reply
  • j_iggga - Thursday, June 30, 2011 - link

    Single and double threaded performance is most important for games.

    Bulldozer has no chance in that regard. The only hope Bulldozer has is that it outperforms a quad core Intel CPU with its 8 cores in a fully multithreaded application.
    Reply
  • L. - Thursday, June 30, 2011 - link

    GPU's are most important for games, that and a CPU that can feed your GPU's ;)

    More and more stuff is using 4+ threads, I'd be surprised if the next benchmark from Crytek isn't vastly multithreaded on the CPU side.

    We'll see anyway, but the design choices AMD made for Bulldozer are definitely good, as were their multicore designs that Intel quickly copied - for the best.
    Reply
  • frozentundra123456 - Thursday, June 30, 2011 - link

    Are you kidding me??? If Bulldozer is so great why do they keep having delay after delay and are showing no performance figures?? Reply
  • HangFire - Tuesday, July 05, 2011 - link

    Given the number of Nocona CPU's Intel sold- as evidenced by the huge number showing up on the secondary market right now- Intel server shipments won't die even if they have an inferior product (again).

    The faithful will buy on.

    L., you seem to be betting on a jump for Bulldozer that will exceed that of C2D over Netburst. I'm not sure that's even possible. C2D only lacked a built-in memory controller, and that has been fixed. I'll be happy if BD even matches Nehalem in core instruction processing efficiency.

    But I agree the more progress AMD makes, the better the market is for all of us, no matter which we buy.
    Reply
  • frozentundra123456 - Thursday, June 30, 2011 - link

    totally agree with your post. Just a weak gpu tacked on to ancient CPU architecture that could easily be beaten by a 50.00 discrete GPU in the desktop.

    I can see a place for this chip in a laptop where power savings is important and it is not possible to add a GPU, but for the desktop, I really dont see a place for it.

    And I agree that Bulldozer is late to the game and may not perform like the AMD fanboys claim. AMD talks a good game, but so far they have not been able to back it up in the CPU area.
    Reply
  • jgarcows - Thursday, June 30, 2011 - link

    Can you use OpenCL with the Llano GPU? If so, how does it perform for bitcoin mining? Reply
  • JarredWalton - Thursday, June 30, 2011 - link

    Yes, Llano fully supports OpenCL -- it's basically a 5570 with slightly lower core clocks and less memory bandwidth (because it's shared). On a laptop, Llano is roughly half the performance of a desktop 5570 (around 40Mhash/s). The desktop chip should be about 40%-50% faster, depending on how much the memory bandwidth comes into play. But 60Mhash/s is nothing compared to a good GPU. Power would be around 60-70W for the entire system for something like 1Mhash/W. Stick a 5870 GPU into a computer and you're looking at around 400Mhash/s and a power draw of roughly 250W -- or 1.6Mhash/W.

    In short: for bitcoin mining you're far better off with a good dGPU. But hey, Llano's IGP is probably twice as fast as CPU mining with a quad-core Sandy Bridge.
    Reply

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