How do I get the most out of my SLI crossfire?

Discussion in 'Player Support' started by libbmaster, Jun 27, 2014.

  1. libbmaster

    Okay, here are my system specs:

    GPU: x2 radeon HD7770-DC series.

    CPU: i5-3570

    When I am running on just one card, I get okay performance on below medium settings. In big battles, my FPS can dip as low as 40, out of battles it climbs to around 90-120. The higher the FPS, the more unstable it is: in an empty field, running around in circles and jumping cause my FPS to rapidly fluctuate 20-30 points. when it gets around 40, it usually jumps around a lot slower.

    When I run crossfire, if anything, my FPS gets worse. Sometimes it's not noticeable, but in big battles it can dip as low as 30, and this is with the same settings as above.

    I see the GPU and CPU bottleneck icons frequently, but one is not particularly dominant.

    I've heard that there are ways to configure your system to make PS2 actually benefit from Crossfire. Any help would be appreciated.
  2. Octiceps

    CrossFire doesn't work properly in DX9 games.
  3. BlackDove

    Tell AMD to make Crossfire work.
  4. libbmaster


    Ah well. Thank you for the replies.
  5. BlackDove

    You should try to use a single one or sell those both and get a Geforce 800 series when they come out.
  6. Lavans

    When there's negative scaling, that generally means there's no CrossFire profile for the game you're playing. Being bottlenecked by the CPU is also known to cause the issue, which is common with PS2. You might be able to alleviate the negative CrossFire scaling, but even if you do, CrossFire won't increase your FPS in large battles where you are bottlenecked by your CPU. What BlackDove and Octiceps is referring to when they say CrossFire doesn't work in DX9 is frame pacing, which is the first and foremost culprit for something called micro stutter. CrossFire does work in DX9, but not as well as SLI.

    Your best bet would be to try switching the CrossFire rendering mode to AFR (Alternate Frame Rendering), or switching the CrossFire profile that your drivers are defaulting to. If memory serves, you can do this from CCC, but you can also do this from RadeonPro. In my experience the Crysis profile, StarCraft 2 profile, L4D2 profile, BioShock profile, and TrackMania profile are good profiles to try switching to. Unfortunately, MultiGPU systems do take a bit of elbow grease to get to work properly with F2P games, and generally any game that's not a AAA title, since AMD and Nvidia doesn't consider them priority games. If you can't find any working CrossFire profile, and if switching to AFR doesn't help, then there won't be a whole lot you can do unless AMD releases a Catalyst Driver with Planetside 2 support.
  7. BlackDove

    Crossfire and SLI(for Radeons and Geforces) ALWAYS use AFR, which means that the GPUs alternate between frames in a 1, 2, 1, 2 fashion.

    Quadros can do SFR where two GPUs appear as one and render the same frame, but Geforces and Radeons do not.

    And the no frame pacing issue means you get less VISIBLE or complete frames than with a single GPU and there is no fix for it. They did fix it for DX10 and 11 though.
  8. Lavans

    Yes and no. SLI uses AFR2. CrossFire does not use standard AFR (I forget what it uses exactly).
    This is evident in the fact that not all games render properly when the CrossFire profile is manually set to AFR within CCC or RadeonPro, sometimes causing the game to crash, a white screen, or broken color palettes.
  9. Lavans

    I forgot to mention that if you do try changing the rendering mode to AFR, make sure you set the MVMPU mode to D3D AFR friendly, otherwise it won't work.
  10. SuperMedicated

    another thing is that the game plain sucks on AMD hardware, be it GPU or CPU the game is badly optimized for both
  11. Octiceps

    Huh, seems absolutely fine on my 7950. You are right about it sucking on AMD CPU's though.