Some few days ago i bought a Sapphire RX 580 Nitro+ 4GB on Amazon, so i remove mi older graphics card from my desktop ( AMD R7 360 ) and i wiped my Hard Disk. So everything was okay, i download all the drivers, all the new stuff, but in some games i have terrible, but really terrible FPS (for example Quantum Break 10-25 FPS in LOW), but in other games l get a lot of fps like it should be (Rainbow Six Siege 80-90 FPS ULTRA). So i checked the overlay of Supervisor Performance on AMD ADRENALIN 19.1.1 AND I SAW THE PROBLEM. The profblem is that the Frequency of the VRAM is very slow, 300Mhz instead of 1750Mhz , some times the frequency is very unstable, like it goes up from 300Mhz to 1000Mhz in a few seconds an then it falls down to 300Mhz again, other times the problem is not the memory, is the GPU CLOCK sometimes is 300Mhz or sometimes 900Mhz, in some games like Quantum Break is super unstable.
I have tried moving the settings from Wattman, and nothing, the problem continues.
Also i have looked some other post about the same problem, but i have tried all the psible solutions but i can't solve the problem.
My Desktop is an ACER ASPIRE T but with other graphics card and another PSU
Intel i7 4790
PSU Corsair CX600M Bronce 80 PLUS
12 GB RAM DDR3 1333Mhz
RX580 Sapphire Nitro+ 4GB
Hard Drive 2TB 7200RPM
I'm pretty sure the thermals are good, i have an gabinet Corsair Spec M2 and two 120mm Fans, so the thermals of the graphics card are between 50 and 68 C° while i play
i have tried a lot of things but i can't solve the problem
also i'm considering change to my old AMD R7 360 graphics card because some games are about the same FPS, other games are better in my old AMD R7 360 but other games are A LOT BETTER.