I've just installed a PNY 512MB 8400GS PCI card in an Asus Pundit P1-PH1 barebones PC which has integrated Radeon Xpress 200 graphics. The aim was to give the graphics a performance boost for games my kids play (it's their PC), such as Rollercoaster Tycoon 3 and Zoo Tycoon 2 (so nothing too demanding on the graphics front).
Unfortunately the "upgrade" seems to have had the opposite effect. Video playback and graphics performance in general is much, much slower when using the 8400GS. I really don't understand it. There is no option in the BIOS to disable the onboard graphics, only to specify the graphics controller to use as the primary boot device. I've set this option to PCI rather than on-board and yet the monitor doesn't display the BIOS splash screen if the PCI card is hooked up, only showing graphics from this card when Windows 7 has started. Device manager shows the Radeon and NVidia devices and if I disable the on-board graphics in device manager then the PCI 8400GS output disappears.
Can anyone suggest what is going on here? The Nvidia driver
I've loaded is the latest from their website.