I seem unable to initialize hardware-accelerated OpenGL on the GPU side of the Intel Ivy Bridge GPU (it's on a Core i7-3700K chipset, with the HD4000 graphics core).
This is a new problem on Windows 8. I distinctly recall having access to GPU-accelerated OpenCL on Windows 7. In fact, it came in the built-in Intel processor graphics drivers.
The symptom that I observe: every OpenCL program I run (whether the program is 32-bit or 64-bit) shows that the Intel OpenCL platform can only execute on the CPU. When measuring the performance, it is definitely slow enough to be running on the CPU. From what I have seen, the GPU side is about 3-4 times faster; I'd like to have access to that on Windows 8.
Am I missing a separate driver download? I've already tried the Intel OpenCL SDK, both version 2012, and 2013 Beta. Still I can only use OpenCL on the CPU, which is very slow compared to what a GPU is capable of.
Best Answer
As far as I can tell, its caused by the installation of Catalyst drivers (e.g. atiumdag 9.2.0.0 via Windows Update).
This deploys a service 'AMD External Events Utility' set to start automatically.
When the PC next reboots it does something which causes cause the IGP OpenGL driver to fail to load.
You should be able to prove this / make a working system as follows:
clinfo.exeAlthough I just disabled automatic updates, installed Catalyst then immediately disabled the service.
Unfortunately while updating to the latest Intel drivers seems to be ok, updating Catalyst to later drivers triggers the the service again.
[Edit]
Have posted these details on the AMD forum, hopefully can find out a bit more about the cause, and how to resolve without a reinstall. I've managed to get my main system to go from not-working back to working but I can't rememeber exactly what I did.
Now that I've got one system running Catalyst 13.1 and the Intel beta driver the performance seems to be actually worth bothing with; LuxMark Sala scores were: