Okay, I'm completely lost
I have no idea how to get my new GeForce 2 MX400 VTO card to work under XFree86 4.2.1. I've replaced a RIVA TNT PCI card, which was working fine, with this AGP card. I'm running Mandrake 9.0 (stock kernel) on a Via Apollo Pro chipset MB with a max 2x AGP slot.
I've tried pretty much anything I could think of, including upgrading from 3123 to 4191. I've tried setting NvAGP to 0, 1, 2 and 3, each in turn, in /etc/X11/XF86Config-4. I've set an option of NVreg_ReqAGPRate in /etc/modules.conf, having tried both 2 and 1.
Everything looks fine in /var/log/XFree86.0.log with not so much as a warning let alone an error. The card is identified and the correct resources appear to be ascribed.
Okay, here's the symptom. X starts fine and runs fine (glxgears turns at about 150 fps) but, after anywhere from 30 s to 3 m, it (almost) locks the entire computer. The cursor will move, like, once every 2 minutes and, if I hit Ctrl-Alt-Bksp at the exact second that it moves I can kill the server, else I have to power down.
I'm tearing my hair out so any advice would be appreciated. BTW, this machine dual boots Win 98SE and the card is working fine in there.