OpenCL

[MicahVillmow]

Tomhammo,
The hardware is capable of doing so, so is something that we are looking into how to properly utilize. So I don't have much to update at this time.

[tomhammo]

Thanks for the info Micah,

I guess leading on from that - if I were to recommend purchasing of 57xx vs 58xx gpu's for opencl development - to a customer interested in concurrent kernel execution (due to small kernels) - would there be a difference between support for concurrent kernels between 57xx and 58xx gpus going forward? i.e. if support is enabled in 58xx (via out-of-order command queues in opencl for example) would it also be enabled in 57xx? do 57xx/58xx support concurrent execution in the current version of the opencl drivers? thanks - Tom

[MicahVillmow]

Tom,
The major difference between the 57XX and 58XX from a compute feature perspective is 58XX has double precision and 57XX only has single precision. For concurrent execution, when one chip gets the feature, they all will get it.

[tomhammo]

Hi Micah,

We have been working with 5850's, with very good OpenCL results. Though a big question still remains regarding concurrent kernel execution... is there a (rough) estimate of when this feature will be available ?

Looking at getting a Fermi board to see whether it is more, or less, cost-effective that 58xx cards - the extra cache would probably not provide much gain for our needs, but concurrent kernel execution might tip it over the edge (e.g. be able to hide the latency of a memory-bound kernel by running it in parallel to a processing-bound kernel).

would prefer to keep our investment in ATI-optimised code if we see concurrent-kernel execution down the track

thank you and regards,

- Tom

[sir_um]

bump.

Any news on Concurrent Kernel Execution? A rough due date, problems holding it back, anything?

This would definately be a huge plus, if CKE were "activated" on ATI cards. (Since it is an issue of driver support)

Without CKE, task parallel computation [queue.enqueueTask() - kernels with a workgroup of size 1] have ZERO performance improvement, by running in OpenCL. Since no 2 tasks can run in parallel, and must be run 1 after the other, even if the OpenCL device has more than enough resources to run both kernels.

thanks,
-Chris

[diepchess]

Sorry for reviving the thread. But concurrent kernels also very important for me so i join asking the question: when is it available?

Is currently work getting done to support concurrent kernels?

Two concurrent kernels would already make life a lot easier and would make programming life a lot easier at AMD gpu's for most problems!

Sometimes 2 concurrent is easier than n

Thanks,

Vincent

Originally posted by: sir.um bump.

Any news on Concurrent Kernel Execution? A rough due date, problems holding it back, anything?

This would definately be a huge plus, if CKE were "activated" on ATI cards. (Since it is an issue of driver support)

Without CKE, task parallel computation [queue.enqueueTask() - kernels with a workgroup of size 1] have ZERO performance improvement, by running in OpenCL. Since no 2 tasks can run in parallel, and must be run 1 after the other, even if the OpenCL device has more than enough resources to run both kernels.

thanks, -Chris