I have been running without problems for a couple of years using a Gigabyte GAX58A-UDR3 motherboard, 6GB Corsair memory, an i7-920 CPU and a EVGA GeForce 8800GTS graphics card, using a Viewsonic VX2453 monitor. Then a few weeks ago I experienced artifacts on my screen when I visit venues with 6 or more avatars. The artifact typically starts at a point at an avatar, then crosses the screen forming a big triangle of a single color. As I cam around, these artifacts disappear and others form, sometimes almost filling the screen. I had a similar issue when I first started in SL, using a entry level graphics card and that problem disappeared when I replaced it with something better. I concluded that my 8800GTS had given up the ghost after many years of good service and acquired a EVGA GTX970. To my surprise, the problem didn't go away! I got in touch with EVGA support who walked me through various clean installs of the drivers. No luck. They offered to replace the card, but also suggested that I try the card in another PC to see if the problem moved with the card. It didn't. The 970 works beautifully in another PC (this one with a slightly faster CPU and 16GB of memory). My question is, what other than the graphics card could create this problem? Any suggestions would be appreciated.