Hi,

On my laptop, when I turn on OpenCL I get the error:

OpenCL Exception: 4:3:26: error: OpenCL extension ‘cl_khr_fp64’ is unsupported
clBuildProgram (-11)


So I looked in the Diagnostics, and lo and behold, while the OGL was using my Nvidia GTX960M, the OpenCL is using the crappy Intel GPU.

Any way to tell Houdini to use the Nvidia card too for OpenCL?

15.0.315 Windows 10

Cheers,

Peter B

Try the these two env variables:

HOUDINI_OCL_DEVICENUMBER=1
HOUDINI_OCL_VENDOR='NVIDIA'

Good ideas, but both give me “OpenCL exception: invalid vendor” or “invalid device number” and then I get no OpenCL device.

HOUDINI_OCL_DEVICETYPE=GPU
HOUDINI_OCL_DEVICENUMBER=0

is the right variable

Actually the Intel GPU will be picked up with DEVICETYPE=GPU, so you really need to use VENDOR. The problem is likely that the string should be “NVIDIA Corporation”, not just NVIDIA. And DEVICENUMBER should stay 0, since that's per vendor.

In H15 there's a command line tool called hgpuinfo that can help debug OpenCL device problems without launching Houdini:


$ hgpuinfo -c
OpenCL Platform NVIDIA CUDA
Platform Vendor NVIDIA Corporation
Platform Version OpenCL 1.2 CUDA 7.5.8
OpenCL Device Quadro K6000
OpenCL Type GPU
Device Version OpenCL 1.2 CUDA
Frequency 901 MHz
Compute Units 15
Device Address Bits 64
Global Memory 12278 MB
Max Allocation 3069 MB
Global Cache 240 KB
Max Constant Args 9
Max Constant Size 64 KB
Local Mem Size 48 KB
2D Image Support 16384x16384
3D Image Support 4096x4096x4096

$ HOUDINI_OCL_DEVICETYPE=CPU hgpuinfo -c
OpenCL Platform Intel(R) OpenCL
Platform Vendor Intel(R) Corporation
Platform Version OpenCL 1.2 LINUX
OpenCL Device Intel(R) Xeon(R) CPU X5650 @ 2.67GHz
OpenCL Type CPU
Device Version OpenCL 1.2 (Build 57)
Frequency 2670 MHz
Compute Units 24
Device Address Bits 64
Global Memory 24102 MB
Max Allocation 6025 MB
Global Cache 256 KB
Max Constant Args 480
Max Constant Size 128 KB
Local Mem Size 32 KB
2D Image Support 16384x16384
3D Image Support 2048x2048x2048


I've been meaning to add an RFE for an additional command-line switch that will list all available OpenCL devices. I'll add that to the bug db now.

Awesome thanks for the info I'll try that when I get home!

Would be nice to see the OpenCL options in the preferences as a GUi.

Yup that did it, thanks!