cancel
Showing results for 
Search instead for 
Did you mean: 

Archives Discussions

KNeumann
Adept II

Re: register usage in kernel again...

Ok I see.

And what about the other half?

0 Likes
MicahVillmow
Staff
Staff

Re: register usage in kernel again...

They are used to launch a second wavefront on the device in parallel to the first device to hide latency. The latency on pre-GCN hardware was 8 cycles, and each wavefront takes 4 cycles to execute all 64 work-items.

KNeumann
Adept II

Re: register usage in kernel again...

Thank you so much for that clarification.

It makes more sense to me now

0 Likes
pwvdendr
Adept II

Re: register usage in kernel again...

MicahVillmow wrote:

They are used to launch a second wavefront on the device in parallel to the first device to hide latency. The latency on pre-GCN hardware was 8 cycles, and each wavefront takes 4 cycles to execute all 64 work-items.

Has this changed in GCN then? In the APP OpenCL Programming Guide this information is still present (bottom of page 4-45) without any mentioning of changes on GCN hardware.

0 Likes
MicahVillmow
Staff
Staff

Re: register usage in kernel again...

We are working on the documentation update for GCN.