Many recent laptop models now come with "switchable graphics"...two graphics cards designed to switch between them depending on the circumstances. Unfortunately, the mechanism for managing these graphics is far from standardized, and each laptop manufacturer has their own solution for management. Looking on Asus' support website, I don't know exactly which utility is used to manage the cards, but I'm guessing it's probably Power4Gear, which is their power management utility.
Alternatively, there may be a BIOS option to force nvidia graphics all the time, but that's probably not what you want.
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:
- Install Windows 8 with a display connected only to IGP
- Optional: When prompted to reboot for updates, disable service 'AMD External Events Utility'
- Install AMD APP SDK 2.8
- Run
clinfo.exe
Although 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:
- ~2050 on the 7970 GPU
- ~2350 running 7970 and Intel HD4000 together
Best Answer
Hopefully this will cover everything:
Intel HD Graphics 3000 supports OpenCL 1.1. It contains 12 execution units. Compare this with discrete graphics cards which, at the high end, can have hundreds of execution units.Hopefully it will become apparent that, while you can run OpenCL jobs on the HD 3000, if you have a lot of such work to do, you would do better to buy a high-end graphics card to run it on, as you would get much better parallelization (and thus performance).