Windows 10 x64, Intel i5-3750K / Radeon HD7850.
Some graphics application (game?) on foreground, another software which uses the same AMD gpu on background.
If foreground application takes a lot of GPU resources (high load) then background app has greatly decreased performance in DirectX graphics and h264 amf encoder (only specific operations are slowed down - surfaces locking, submitting input frames to encoder).
I tested previous AMD Radeon drivers, no luck. Other encoders like h264 nvenc and qsv work good on background. AMD radeon video card is primary and connected to display, other devices are not connected.
Software, which worked fine one month ago (and years before), became very slow in provided conditions.
Another test system has RX580 video and has absolutely the same problem.
I hope, I was clear in the description.
I'd like to see AMD developers suggestions.
p.s. Windows 10 Game Mode is turned off