More for the databaseMy 8790 was purchased used from ebay about a year ago. Didn't have any problems with the wacky artifacting until about two months ago. Uninstall drivers, reinstall drivers, roll-back drivers, etc. etc. Finally got around to checking here.
I don't have time to read all the posts in this thread, so my apologies if I am repeating others' experiences. For the latest attempt-to-fix, I completely removed the heat sink from the processor and removed some of the cute "don't burn or cut your fingers, ignorant user" cover paper from the sink so it could be *thoroughly* cleaned, and cleaned off the old processor goop and replaced it with new. I considered trying to remove the paper-glue residue from the sink, but could not think of anything with which to remove it that would not cause the laptop to burst into flames. But, hey, that might not be so bad at this point. Entertaining, anyway. The artifacting was greatly reduced after 24 hours, but not completely eliminated.
Next, according to advice of users in this forum, the laptop keyboard was flipped over on its face off the graphics unit cover, and the screws removed from the cover. (Since this is a desktop replacement, I've always used a remote keyboard/mouse anyway.) So far, no artifacting.
I'm going to let the laptop run a few days as is. Then I will remove the rest of the stupid-user paper from the processor heat sink. Then I will competely remove the cover plate from the graphics card and put the keyboard back on and see if it melts : ) The keyboard plate has a lot of ventilation and I won't be typing on it anyway. I'm thinking the graphics unit would function better without the relatively solid cover plate. If this works, I may try beefing up the keyboard so that it is not so flexible and rigging some motherboard-type standoffs or grommets to keep it off the graphics card. Or I may cut/punch some big holes in the cover. I'll report back on my experiments.
I have three Sagers. All big-honking-laptops are very heat/dirt sensitive, but it's too bad that the 8790 is *so* *very* *poorly* heat-engineered.
Although the common recommendation is that processor goop doesn't need to be replaced, my experience has been that the Sagers benefit from new goop after 2 to 3 years.
I have hardwood desks, so I've always used laptop coolers of various sorts.