CrossfireX causing problems under Win10; HD6990 card

My problem is straight-forward: Ever since switching to a clean-install of Windows 10 64-bit, CrossfireX has been messed up for my HD6990; and none of the different Win10 drivers solve the problem. Under Windows 7 (64-bit) it pretty much worked fine. BTW, I'm using MSI Afterburner for manual fan control - which wasn't a problem under Win7 and shouldn't be a problem now).

GPU-Z says that crossfire mode is enabled on both devices, and ULPS is disabled, BTW.

Symptoms:

Some* games and full-screen apps will "flicker" badly in Fullscreen mode when CrossfireX is enabled - kinda like page-tearing but a bit different (it's clearly an AFR problem). Even the PCIE bus-test render in GPU-Z shows this problem when in fullscreen. GPU-Z and Crimson both say that the two GPUs are indeed linked and crossfired up properly, btw.

They stop flickering when games are set to borderless window mode (Crossfire is being forced to deactivated);

Trying to disable crossfire in the control centre or crimson has absolutely no effect whatsover (the drivers appear to be ignoring that command).

Switching to different methods of crossfirex doesn't fix the problem, nor does toggling frame-pacing.
Turning of ULPS has done nothing.

I've done a full wipe and purge of all video drivers on the system and clean installs with all the windows10 (64-bit) drivers released to date, although some have disabled crossfireX support altogether, none have actually address the problem.

Having "enable crossfireX for games without a profile" unticked has no effect.Toggling v-sync has no effect.

Now that HD 6000 series is considered legacy there's apparently going to be no more drivers, and with none of the existing Win10 drivers actually working right I'm kinda boned. Are there any community drivers? Or a community repackage of working Win7/8.1 64-bit drivers that might address this issue?

I've tried manually installing the Win8.1 drivers, but Win10 doesn't want to revert to an older version; and I can't seem to find the exact driver files to force it to manually.

Any third-party apps that could sort it?

I'm really desperate - I've been fighting this issue ever since installing Win10, and I'm getting to the point where I've exhausted everything I can think of.

I've even tried pulling the card out and double-checking it's seated correctly (it is fine, of course) in case it was something as simple as a hardware issue that just happened to perfectly coincide with Win10.

*Some games are fine: For example just tried Elder Scrolls online - puts both GPUs under load correctly, no problems with the rendering whatsoever.
U3 games are negatively effected, as is League of Legends and many others.

 

Possibly fixed

Looks like I've may have fixed the problem.

I grabbed catalyst 14.9 WHQL drivers and unpacked them following the instructions on Kn00tcn's site.

And by dumping atiumdag.dll / atiumd64.dll into affected games' folders (specifically League of Legends at time of posting) it has apparently solved the problem.

It's too early to determine whether it's just found a new way to break crossfire (in which case it's no better than just pointing Crimson to CrossfireX disabled profiles like APB.Exe / turning crossfire off in Crimson) - but so far it's promising.

 

As a fellow 6990 user i've found crimson 15.11 and 15.11.1 having issues with crossfire in dx9 games.
An example is CS:GO and L4D2 in fullscreen with crossfire activated, the screen goes black and i can only see small parts of the screen, its an horrible flickering where i cant even see the game opened at all. I can post a screenshot later if i can.
In borderless mode the game runs fine. I've found that disabling crossfire doesn't do anything too.
However I don't have the issues you have in all games.
Had to roll back to pre-crimson drivers as I play CS:GO a ton.
Could it be ULPS ? I don't have it enabled.

 

So far I'm pretty sure that the problem is with the Win10 catalyst drivers just being obnoxious.

It looks like the solution I outlined above has solved my problem, so I'd strongly recommend giving it a try.

Worst case scenario is you've wasted a little time unpacking the dlls and just remove them from the games' folders if they don't fix your issue.

I'm so confident of its efficacy that I've replaced the DLLs in my system64Wow folder with those two in order to make the solution global.

If I find a handful of games need newer drivers, I can just put the 15.11 dlls in those games' folders instead.

As for ULPS, if you install GPU-Z and use the drop down at the bottom to alternate between your two GPUs it should tell you if they're linked and if the secondary is in ULPS mode. I turned ULPS to try and trouble-shoot, but pretty sure it wasn't causing me a problem.

Edit: Some additional .dlls are needed to solve some videoplayback issues. Rather than trouble-shoot it, I just did a full wipe and clean install of the 14.9 whql drivers found here on Guru3D - the old catalyst has more options than crimson, so a full rollback seems to be the way to go ATM.