2 replies to this topic

[Chrithu]

For a lack of a better place for bringing this up again I am posting it here. It is a problem being present since MWO's beta and I just don't want the devs to forget about it.

So where do we stand as of now:

It's pretty much known that Crossfire works, giving a huge performance boost, when setting it to "AFR-friendly" in the Catalyst Control Center. But that comes with a nasty screen flickering.

Any other default crossfire mode either taxes both GPUs only for 50%, resulting in no performance gain or sometimes even a loss, or uses only one GPU at 100% again resulting no performance gain or even a slight loss.

Then we have those workarounds using a Crossfire profile of other games (mostly "Bioshock.exe" and "Borderlands2.exe"). With those both GPUs are used and some people even report more stable FPS and slight performance boosts. For me personally this never worked great.


As I just today started playing again I naturally revisited this stuff and found this all to still be true in the second half of 2015. And all this stuff is known since 2012.

Anyways in an attempt to figure out what is up with the flickering in AFR mode I noticed, while playing around with stuff, that when hitting 120 FPS, the flickering turns into a darker halfscreen wandering down. Obviously an effect similar to when carwheels reach a frequenzy on which the rims actually look as if they are spinning slower and even backwards.

Anyhow I tried to screenshot it but naturally did not get half the screen light and half the screen dark as I thought I would. But when going through the screenshots in the gallery I found one that is darker than the other (best visible if you DL them and view them in a gallery after each other).

LIGHTBULB!! Of course, as AFR renders every other frame on one card it is obvious that the flickering is caused by one card rendering darker than the other.

Whether this is an issue with lighting or not I do not know. Anyways I hope this info may help PGI to tackle this problem and fix it. Maybe the guys from AMD can help them. I've heard they do that.

Edited by Jason Parker, 13 August 2015 - 10:58 PM.

[Shamous13]

try putting these lines in your user cfg also make sure that ultra-low power state for your video cards is turned off

r_MultiGPU = 1
sys_budget_fps = 40
sys_MaxFPS = 65

[Chrithu]

Shamous13, on 14 August 2015 - 06:11 AM, said:

try putting these lines in your user cfg also make sure that ultra-low power state for your video cards is turned off

r_MultiGPU = 1
sys_budget_fps = 40
sys_MaxFPS = 65

Just to repeat the OP in short: The problem is that Crossfire only gives a performance boost in "AFR-Friendly" mode (doubles the FPS for me) but that comes with a nasty flickering caused by the frames being rendered darker on one card than on the other.

The settings you suggest hardly can change that (r_multigpu is set to 1 already anyways). All they do is help further stabilize the FPS when using the "Borderlands2.exe" and "Bioshock.exe" profiles from which you don't gain any noteworthy performance boost.

Still appreciate you trying to help, been tweaking around with crossfire since closed beta though, so I know all the tricks we can do from our side. It's up to PGI to do something themselves or get in contact with Crytek and AMD to get help.

Edited by Jason Parker, 14 August 2015 - 06:30 AM.