DiffEqFlux GPU example slow

[ChrisRackauckas]

@acse-ogb119

Is this example expected to be much slower on the GPU? e.g. maybe because it is a small problem size and the overhead of copies to and from GPU memory is a bottleneck? Do others experience the same performance issues with this example?

It’s not a performance issue. It’s just because CPU matmuls of that size are faster on CPU. Did you try

A = rand(50,50)
b = rand(50)
@btime A*b
gA = gpu(A)
gb = gpu(b)
@btime gA*gb

You can make the example bigger and bigger until GPUs finally make sense. You need pretty big problems for GPUs to make sense if the CPU code is optimized. You can also batch data points which would help here.