I've had the 'random lockup' problems when running q3a on my Guillemot DDR Geforce under win2k and NT ever since the AGP enabled drivers came out. I've finally managed to get it working reliably with the 3.75 drivers.
I replaced my 275W power supply (which was inadequate for this machine even without the GeForce issues) with a 425 one - it can feed the 3.3 line with up to 40A. One of the characters from ABIT who posts on usenet claims the GeForce can draw up to 16A under heavy load (which is more than the 12 to 14A most psu's provide). The combined power output for +5V and +3.3V is 300W, compared to the 150W on my old psu. Again, posts by abit people indicate that 150W _minimum_ on 3.3V and 5V is required for the BP6 to operate properly.
I still had problems after replacing the PSU but they were less frequent. I then moved the PCI card right next to the AGP slot to another slot to create more space and to improve cooling. I also pointed one of my case fans directly at the geforce. After that I was able to run q3a in smp mode (3.75 drivers) both on win2k and nt (latest reference drivers) without any problems. I've run at least an hour's worth of timedemos in various configurations without problems - my old setup would lock up within one or two demos max.
I'll probably look for a better heatsink/fan for the geforce gpu itself to nail cooling completely and move my case fan to its normal position.
 
Here are my system's specs:
BP6, 2 Celeron 466, 66FSB
256MB PC100 ECC SDRAM
GeForce 256 DDR
SB Live Value
3Com 3C905 EtherLink 10/100 NIC
DTP Decade Smartcache V SCSI RAID Controller
two 9.1GB Atlas IV LVD SCSI Drive, RAID 0
Kenwood TrueX 72x IDE CDRom
Castlewood ORB Drive, IDE Internal
Generic floppy
425W PC Power & Cooling PSU
 
I'm running NT4 Server sp5 and Win2k Server final. AGP Apeture size is 128MB.
 
-pvg
 
P.S. Hmm, looks like I picked the wrong icon for this topic... Was supposed to be a thumbs up.
 
 
[This message has been edited by pvg (edited 14 February 2000).]