So my computer is working on it's 3rd graphics card right now and I have just seen this one start artifacting as well.
Originally I had a Nvidia 8800 Gts for about 2.5 years. That began artifacting so I got a replacement from eVga. They sent a larger 9800 presumably because they had no 320mb 8800's laying around. This card was slightly more monsterous and took only 3 months to start artifacting hardcore.
Last week I borrowed my roomie's nvidia 9800 gt on the off chance that I was just having bad luck with cards. Well now my buddies card is just starting to show artifacts in games as well.
The nice man at EVGA cooly demanded that I purchase a 2nd power supply if the new replacement card goes bad...
We checked my hardware in BIOs and the power seemed stable. Could it be something else?
AMD 64x2 5600 2.8ghz
Asus m32mn mobo
various g. cards
Rosewill 500w PSU
500W PSU should run a 9800 card(125W) the 8800GTS was (145W), do you have the newest drivers? I think 257.21 is the newest, run OCCT PSU test, if the PSU is weak it may kill it though, and weak PSU will kill the mem chips on the vid card
check the currently artifacting card in another system just to make sure it isnt something in your system generating the artifacts.
What 500W rosewill PSU do you have? Many of their older cheaper models have poor ripple suppression and it might be beginning to damage your hardware if its filtering has gone. It might be safest just to replace the PSU on principle to make sure anything you replace the GPU with wont get damaged by a bad PSU.
if the cards are older, the next thing that it might be is the MB itself, but this is guessing, all the cards were old, so -- there's a lot of room for guessing, and in the end you might find that everything is OK, old age is a terrible thing, test all you can, memtest86 for the memory
GPU temp 104c - Yikes!
Sounds like in addition to a slightly dodgy PSU your case has poor ventilation if its getting that hot! That kind of heat on a 9800GT will be cooking the card and will be causing artifacts and crashes.
I'd sort out some case fans and/or a new case too.
this is not a case without fans people..i should have taken a picture.
it pulls air in the front, has a decent cpu fan with side vent and another fan on the back that pulls air out.
I posted this quite a while ago and here is what I have found out since then:
my PSU was undervolting hardware causing it to fail. (2 graphics cards)
my motherboard was having some mysterious issues as well. One or more of the memory slots was not functioning...the memory was good.
asus is replacing the mobo for free after 3 years of usage. Evga is also handling replacement fairly well.
what i learned:
-don't buy a cheap power supply ever.
-testing hardware temperatures and volting is very important with the super uber ultra clocked versions of the same hardware are being used. ie. 3 foot long nvidia cards.
-don't buy a new computer if only one game out currently pushes your computer.
-planned obsolescence is a bitch.