Here is the description of problem:
During game play, any game, I'll experience a sudden FPS drop that will last for 10~20 seconds, and then it will disappear. The FPS drops will reappear again at a random timing during the game and will continue to occur.
There's no specific trigger to it.
When there's no FPS drops, I experience FPS>60 and sometimes up to 120FPS.
This happens only in Crossfire, NO eyefinity and I roughly experienced it since I incorrectly flashed the BIOS of the main GPU to the secondary GPU. This happened last year.
Two R9 290 Gigabyte OC edition in CrossFire. Although, both are same brand and edition, they did have slightly different parameters and I guess different BIOS
Windows 10 x64 Creators edition - Which seems to also be causing issues with CrossFire and Eyefinity.
Is there a way to know which is the correct BIOS for my 2nd GPU? Is a serial number or a sticker on the GPU will help to know that?
It could be a different cause, but since I tried all the drivers I could, and since it happened before the 1st major Windows update, I suspect it's the BIOS.
The other evidence is that when I disable crossfire, this issue doesn't present itself.