Is this card defective, or am I only seeing a power supply, driver or other issue? Generally, how do you diagnose or reproduce such an issue (under Windows) for the repair technicians?
I’m using a compositing window manager (KWin) for my desktop (i.e., one which renders all windows to a texture and displaying that with optional zooming and panning effects). Block artifacts eventually appear on the desktop (actually on the texture, as they seem to ‘stick’ to a certain area of the desktop even when zooming out). Each appears to be a random bitmap of about 16x16 pixels large and each has a single color with transparency (i.e., each pixel is either lit 100% to the color for the block or transparent). Each block seems strictly aligned to a grid that has the same cell size as a single block. A block disappears after window content is refreshed (screen part gets overwritten).
The card is new and has never been overclocked. It has started to show these artifacts after the first or second week. It has not been used interactively in the first week (i.e., I have no data whether it produced these signs out of the box) as the computer was running burn-in tests.
As a quick test, replacing the card with an nVidia 9500 GT does make the artifacts disappear, but of course it is not a solution.
Using openSUSE 12.1 (x86_64) Asparagus;
Linux 3.1.9-1.4-desktop #1 SMP PREEMPT Fri Jan 27 08:55:10 UTC 2012 (efb5ff4) x86_64 x86_64 x86_64 GNU/Linux;
nvidia NVIDIA-SMI 2.285.05, Driver Version: 285.05.33;
GPU card: Gainward nVidia GTX-280 3GB.