OpenCL and multiple GPU's

[art3mis 56]

Any OpenCL experts able to tell me whether OpenCL is 'multiple-GPU' aware? Just wondering if there are any sim performance advantages in enabling OpenCL on multi-GPU systems...

[Daryl Dunlap 11]

Is there even a way to disable OpenCL on compatible devices?

My understanding is that OpenCL will use GPU, and if not available, will fall back to CPU.  That's the reason its safe to use OpenCL SOP in HDA's.

Edited November 10, 2017 by Daryl Dunlap

[schwungsau 281]

openCL nodes in houdini does not support multi GPU, it just runs on the first GPU in the system. it has only a fallback option to CPU.

basicly, openCL is runs on everything at some some time cpu and gpu but current houdini does not support it yet,

 

 

[Guest tar]

On 11/11/2017 at 7:32 AM, schwungsau said:

it just runs on the first GPU in the system.

you can set the env variable to choose which device HOUDINI_OCL_DEVICENUMBER = 0

[schwungsau 281]

16 hours ago, marty said:

you can set the env variable to choose which device HOUDINI_OCL_DEVICENUMBER = 0

didn't work under houdini 16,  at least on my system at the time.

[Guest tar]

6 minutes ago, schwungsau said:

didn't work under houdini 16,  at least on my system at the time.

Not sure why as it's worked since H12 at least.

[cgbeige 0]

ya, the env var works but you have it wrong there. It's HOUDINI_OCL_DEVICENUMBER=0 with no space. 

[Guest tar]

3 hours ago, cgbeige said:

ya, the env var works but you have it wrong there. It's HOUDINI_OCL_DEVICENUMBER=0 with no space. 

The space is fine when put into the 'houdini.env' file but not with a shell environment variable export