I am working on a project where we plan to use an AMD GPU (probably 7850) as a compute only device (using openCL as API). For that we would like to run it without attaching a display - the display would be run from the integrated GPU of the system instead.
However AMD GPUs seem to be disabled if there is no display attached (they cannot be queried from openCL nor from the Catalyst Control Center). This happens both if you start your machine without a display attached and if you detach a display runtime.
Is there a workaround for this? an upcomming fix?
Note that NVidia GPUs have no such problem.
My test configuration is as follows:
CPU: Intel 2600K
OS: Win7 64bit
GPU: AMD 7850
Display Driver: 12.4
I'll be happy to provide more information...
Solved! Go to Solution.
Hmm.. well.. checking your facts before asking is a good idea
You CAN use the GPU from openCL even if it is running headless. I am very sure this was a real problem with previous drivers so when I saw that the HW info still disappeared in CCC when running headless I simply assumed the old problem still existed. Sorry to bother you all!
A follow-up question could be: Why does the hardware info disappear in CCC when running headless? The performance tab with AMD Overdrive controls and tempature information etc. also disappears and that could be equally relevant for a compute only device.
Hi carstenskjaer,
Can you provide the information about clinfo? Thank you.
Hi Wenju
I cannot seem to find clinfo. I've installed APP SDK 2.7 and I can't find it as an .exe nor as a project in the samples. Can you help me locate it?
you can see clinfo .exe under c:\windows\system32\
By design AMD OpenCL is fully supported on headless GPUs.
Please verify the driver is correctly installed in the device manager.
The driver seems to be correctly installed and the 7850 functions fine in openCL and can drive my secondary display without problems. If I disconnect the display (remove the cable) I cannot use the card anymore in openCL.
This is a shot of my device manager (it doesn't change when detaching the display cable)
This is a shot of CCC with cable attached:
This is a shot of CCC with cable detached:
Hmm.. well.. checking your facts before asking is a good idea
You CAN use the GPU from openCL even if it is running headless. I am very sure this was a real problem with previous drivers so when I saw that the HW info still disappeared in CCC when running headless I simply assumed the old problem still existed. Sorry to bother you all!
A follow-up question could be: Why does the hardware info disappear in CCC when running headless? The performance tab with AMD Overdrive controls and tempature information etc. also disappears and that could be equally relevant for a compute only device.