Upon purchasing a 4k monitor, I've had countless issues with numerous games using crossfire. Crossfire no longer works at all in many titles, such as War Thunder and Elder Scrolls Online. The issue occurs in full screen with the latest drivers. The games where crossfire does work still yields more problems. The GPUs reach 100% usage, but the core frequency typically stays around 400-700 MHz, resulting in low fps. It's also worth mentioning that the GPUs are not overheating. Examples of this are Borderlands 2 and The Crew. Not sure what I can try at this point; I appreciate any help.
Here are my relevant system specs:
GPUs: 2x Sapphire R9 390 + 1x XFX R9 390 (3 Sapphire R9 390s won't fit)
Motherboard: MSI Gaming 5
OS: Windows 10 64-bit
Monitor: Samsung U28E590D
Thanks for the help.