geforce 6800gt - sux for farcry? :((

Im having an interesting problem with my geforce 6.. its a PNY Geforce 6800 GT 256mb, which i bought to replace my 9800XT (which is going to my brother).

Before installing the geforce and its drivers, i uninstalled my ati drivers and utilities using the uninstall utility in add/remove programs.

I installed the latest geforce drivers from the nvidia site, version 61.77 for winxp. At first, the card seemed to be performing as expected -

12k score in 3dmark03
51k mark in aquamark03
4.6k or so in 3dmark05.

doom 3 runs like a dream, but i was having a problem with farcry.. i installed patch 1.1 to get rid of the bugged textures,a mnd 1.2 to use ps3.0, but farcry was running very poorly. Even with video sync on, polygons split (a LOT), and the lighting effects are bugged. It also crashed, completely freezing the system, on several occasions. Also, in 3dmark05, i noticed that polygons were splitting too, suggesting that it may be an overall problem rather than jsut a problem with farcry?

I tried reinstalling farcry with only patch 1.1 installed, but the problem persisted. Other games, such as doom 3, need for speed underground, halo, and ut2004 seemed to work fine.. When i put my 9800xt back into my system, farcry ran perfectly well...

My system:

Athlon XP 3000+ (2.17 ghz)
1 gig ram (jkingston value ram ddr400 pc3200 512mbx2 @ 166mhz (333 mhz fsb dual channel)
MSI K7N2 Delta (nforce 2 ultra 400 chipset)
PNY geforce 6800 GT 256mb

Any advice on what could be wrong + how to sort it out would be greatly appreciated.

Thanks for your time and help in advance

What kind of PSU are you running in that system? Could your voltage rails be running low? I know the new nVidia cards are power hungry. You would want a good quality 450W PSU.

XP2800+, Abit NF7, 1GB Dual-Channel DDR333, ATI R9800PRO 128MB, TT PurePower 420W, LG DVD+-R/RW
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