Problems with concurrent streams and overlapping transfert with computation

Hy,

I am trying to overlap some of my data transferts with computation.
In this goal, i created 2 streams, one for the memcpys i want to overlap and one for computation. I am using cufft and i have done a “cufftsetstream” on the compute stream.
But, as you can see on the image attached, the overlapping doesn’t occur and i can’t find any theorical reason for that.

Does anyone have a clue for me?

Thanks
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