ASROCK 939NF4G cant disable onboard VGA

[Anubis1980]

Hi. ive tried to disable my integrated gfx andf i cant, ive emailed asrock and as of yet when they do decide to reply they havent been helpful. ive selected the AUTO option in the allocate ram to video card section and then inserted my new leadtek 7950 gx2 which according to asrock, should disable to onboard gfx. but it allocates 64mb of ram to the card AND windows still finds it! making my pc crash if im not fast enuff to disable the onboard in windows when i install new drivers. i cant turn it off at all. Also when i go to the select what card you would like to use as primary option in the bios. I choose PCIE which is what my 7950 is, i cant see anything, the screen is black, i have to use my old onboard to change the settings back from PCIE to PCI, unplug and replug in my new 7950 until i can see anything. so the PCIE wont function, does anyone know why this is? the card works fine when i select PCI under the bios, just wondering why it wont at PCIE.

The card seems very slow. Aquamark3 gets (after cpu overclock) 97000, i was expecting much more from this, so im assuming the onboard is interfering with the speed?

PLEASE help lol. i like this motherboard and dont want to have to get a diffferent brand.

thank you