What to upgrade first?!

you can see what fps your getting in game on doom 3, just open up the command console ( Ctrl + Alt + TAB i think) then type in com_showfps then to disable the 60fps limit type in com_fixedtic -1, i cant remember if you should have a space between fixed tic (fixedtic OR fixed tic)

if its all jurky still, sounds like either needing to reinstall windows tottall and then if still the problem persists, some hardware problem, sounds more like bad stick of ram, but this crashing can occour if all power connector's are not plugged in, are you sure the PCI-E Power Connector is plugged into the graphics card properly?

maybe bad powersupply problem, bad ram, or faulty graphics card, and if you buy a new graphics card, get a 256mb 7800gtx, there aint much performance increase with the 7800gtx 512mb i think.

if somthing in your system is faulty but not your graphics card, and then if you go and buy a new graphics card, i think you will have the same effect in games :\

 

Yes there is quite a good performance increase with the 512mb GTX card, since not only does it have twice the RAM but ramped clock speeds. However its not worth the huge cost.

 

the 512mb gtx card is only for bragging rights at this moment in time, the cooler looks ace on it though .

 

Well it does give an increase in performance with RAM that runs at 1700MHz+ and core speeds over 580MHz+...it's not worth the massive amounts of money though.

 

You should still get decent fps on Ultra. And with Ultra quality AA and AF are automatically cranked up so there's really no changing it. Plenty of people play it on ultra, you don't need 512Mb's, yes it will run better but the sheer power of the GT is enough to punch through the game no prob. I'm pretty baffled by all this really. But I guess if you need a new card you might aswell get the best. Just RMA you're GT.

 

Unlike past memory bumps on video cards, the GeForce 7800GTX 512 does more than add more RAM on the card. First, it's coming as an official, new product from nVidia. This is the first time this has happened. Yes, you can slap 256MB on a GeForce 6200, but nvidia hasn't gone out of its way to create a new GPU for running with 256MB. Some nVidia parter did that, as the GPU in question was built to be able to work with that much RAM. While the 7800GTX 512 is certainly a premium product, at least this time, there's a significant performance increase with it.