Hi,

does anyone know a way to determine which of the build in GPUS runs opencl? I want the card that isn' plugged to a monitor to work on that. Any way?

Just set the env variable HOUDINI_OCL_DEVICENUMBER to 0,1,2 etc.

Cool, where do I have to put this line? In the houdini.env file?

Tried to paste “HOUDINI_OCL_DEVICENUMBER=0” (or with a 1) but didn't change the device.

You may have to set the vendor too if you have disparate gpu cards.

HOUDINI_OCL_VENDOR
Specifies the platform vendor to choose when creating the OpenCL
context Houdini uses for OpenCL processing.

So I have to copy “HOUDINI_OCL_VENDOR” somewhere in the env file or how do I set the “vendor”? And after that just the opencl devide code line?

well which gpus do you have?

A titan x Hydro copper (Maxwell) and a gtx 1080 Ti (driving the display). Since the titan has effectively more available memory (by nature and by not having to drive a display) I want her to run opencl.

so they are both Nvidia devices, then the Vendor isn't needed to be set.
If you type ‘hgpuinfo -c’ in the Houdini shell what appears?

Well, this:

then do:

export HOUDINI_OCL_DEVICENUMBER=1 ; hgpuinfo -c

and screenshot it.

Still not changing device

hmmm - ‘export’ is for shells not the env file. Remove the ‘export’ bit

Well, I had it without “export” beforre you told it to me. I also tried to paste it in the shell, put different numbers in the line etc.

The command “export” does not exist in Windows “shell”. Use the command “set”. However, this will only last as long as the command window is open. In order to make a Windows environment variable permanent, you need to set using the control panel or Settings. In Windows 10 run Settings, then search for “environment variables”, this opens “System Properties” dialog which has an “Environment Variables” button, which opens yet another dialog where you can edit environment variables.

Now, I have no idea if this the correct method to fix your problem, but I just thought I would stick this in to help folks that need to set Windows environment variables.

Ah, the set function actually worked. If I get this to work permanently: great!

So in the system variables I just have to paste “HOUDINI_OCL_DEVICENUMBER=1”, right?

Well…no….the “hgpuinfo -c” tells me that the titan is used for opencl but the performance monitoring during a sim tells me that the 1080 is still used.

Also its not accepting the variable in the windows properties. Did anyone ever get this to work correctly?

Yes, multi-cpu setups are normally quite easy to setup and use, just not sure you are doing the normal things to test it, such as removing the 1080 card, swapping pcie slots et al.

If the environmental variable isn't working properly then its a bug and should be sent into SideFx. Much quicker than the piecemeal method being done here.

Talked to the support.

The only thing that works is to extend the code a bit:

HOUDINI_OCL_DEVICETYPE = “GPU”
HOUDINI_OCL_VENDOR = “NVIDIA Corporation”
HOUDINI_OCL_DEVICENUMBER = 1


Now it works