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Multi-GPU scaling

Question asked by boxerab on Oct 15, 2016
Latest reply on Oct 31, 2016 by tugrul_512bit

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.

Thanks!

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