I have two RX 470 cards. I am running a series of OpenCL kernels which are fairly memory intensive : this is a video compression application, so a lot of data passes from host to GPU and back. There is also high CPU usage.
When I run my kernels on a single 470, total frame rate is 40 FPS. When I use two 470s, frame rate equals
60 FPS. There is no dependency in the code between the two devices.
So, it looks like scaling is sub-optimal. I was hoping/expecting to get around 80 FPS for two cards. What factors may be affecting compute scaling on multiple cards?
How can I trouble-shoot this issue?
Any advice would be greatly appreciated.