r9 295x2 trifire with r9 290x not working in some games

0ulooked

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May 24, 2015
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As the title states, in some games one (or two) of the gpus will remain completely idle at 0%.

I have no problems with GTA V, Shadow of Mordor, and ACU. I do however have a problem with Crysis 3 and Fallout 4.
Crysis 3 will only run on 1 gpu (even though it was running fine on 2 gpus before I installed the 290x) and fallout 4 will only run on 2 gpus.
I know for a fact that these two games support 3/4 way sli/crossfire so what's the problem?

Before you say I have a crappy cpu/psu, no I don't. i7 6850k , EVGA G2 1300 watt.

32gb ddr4 Ram, and all GPUs are running at stock settings.

My setup runs perfect in every benchmark and the games I stated above.

I do have ULPS mode enabled, I'm not sure if that might be the cause of the issue in Fallout 4 and Crysis 3.

BTW I'm playing in 4k max settings with Vsync off.
Any help will be appreciated.
 
Solution
sorry, is the System.cfg
is in the game folder
first do a backup of the file, then open the file with notepad then find the r_multiGPU and put a 1 in the value
then save the file and test the game

maugusto

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Jan 2, 2016
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because is a single card with 2 gpus, the games is not fully recognising the card, you can try this:
on your user.cfg there is a option called r_multiGPU
by default the value is set to 2 (that means auto detect)
0 is forcing disable and 1 is force enable
try to put the r_multiGPU = 1 and see it is changes the gpu usage

same thing on fallout 4, somewhere in the game options/user cfg, is a gpu command
 

0ulooked

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May 24, 2015
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where do i find these files?
 

maugusto

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Jan 2, 2016
441
0
5,160
sorry, is the System.cfg
is in the game folder
first do a backup of the file, then open the file with notepad then find the r_multiGPU and put a 1 in the value
then save the file and test the game
 
Solution

0ulooked

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May 24, 2015
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4,540


Actually I fixed everything by connecting the display to the video card on the top PCIe slot.
I guess some games were confused because the display was connected to the bottom card (r9 295x2).

Thanks for your help anyways dude.