Hello, I got myself an xfx 9800gtx about 3 months ago. I got a new ps yesterday (antec neopower 650w), right after I installed it the problems started dun dun dun.... ok ok so I start the computer, once it gets to the bios suddenly it starts complaining about the o'c ive been using for the past 4-6 weeks has failed. So I downclock it and it starts fine, I just guessed that my pc needed to get used to the psu and afterawhile i would be able to oc it back to regular speeds again. So everything worked fine for a while (1-2 hours playing lfs) suddenly everything started freaking out (tones of honeycomb-like artifacting) so I start freaking out (lol) I restart my pc and everything seems fine..... untill I start lfs to see that its artifacting, not as bad as the previous one, but theres still some artifacting. So I decide to downclock the videocard and it seems to work, games still like to freeze more often (1-2 freezes every 10-20 mins which makes me have to minimize and open out) THEN nvlddmkm starts acting up more then usual and game me bsod (bsod told me the cause was nvkddmkm.sys) Which im not sure is my fault or the cards f-f-fault.So I decided to reinstall my old psu (cooler master 500w which i've used for the past year and a half) and rma for a refund the antec psu. Even with the old powersupply my gpu is still being retarded, and today my gpu told me i couldnt change my fan speed, in evga precision its not letting me adjust the fans anymore, which it was letting me adjust the day before. I'm thinking i just fried my gpu with a defective psu "oh great!" so now i'm switching to ATi to try out their line of cards (a sapphire hd4870 512).
I need your comments cause I still want to figure out what happened to the card, (did I fry it?/driver (180.48) error?/format (rofl)/). It runs just fine when I dont play any games and idles at 45*c (it used to Idle at 35*c before the fan stopped listening to me).

Setup
Intel E7200 (dual core) 2.53 @ 3.61
Mushikin 4x1gb @ 960mhz
Asus P5KC
XFX 9800GTX+ @ 800/2000/1130

if it has killed your gpu make antec buy you a new one.

Quote from Luke.S :

if it has killed your gpu make antec buy you a new one.

Another brilliant and thoughtful comment from Luke.

Your overclocking things, which means you've voided the warranty. I've never been one for overclocking graphics cards, for the 1-2 FPS increase it gets you in most games (especially LFS being CPU based) its not worth halfing the life of your card.

You may have just nacked the card up by overclocking it. Take all the bits out of your computer, get the dust out of them and rebuild it. If it still doesn't work try another graphics card to see if its the 9800 that you've broken.

I doubt the new power supply broke your card, I dunno why you'd jump to the conclusion that a power supply would break anything when you've been overclocking the shit out of your entire system.

Like mcintyrej said, remove everything, clean it then run it a regular speeds and see what happens.

p.s. If you downclock something I'd say that would mean going lower than factory settings and not restoring it back to what it's supposed to be.....and overclock to regular speeds made me laugh cause thats just overclocking.

Could it get overheated? I also have this problem when I forget to put the fanspeed to 100%. Its a very annoying fan but it does its job. After done playing I revert it back to 40-50% which is alot better.

Ati 4870 here.

isn't something wrong with your cooling Takumi?

Quote from Bose321 :

isn't something wrong with your cooling Takumi?

such as?

Ok, i'll go rebuild the computer and lower the clocks a bit. I'll probably go for 3.2/940mhz (ram)/stock settings w/ the videocard. Sorry if it seemed i just jmped at anything, I was just surprised because right when I started the new powersupply, all (almost) my settings that i have been running for the past couple of months failed, so maybe it was just a coincidence. Thanks for all the help ill go try that right now.