Well, it's a good idea to upgrade the PSU, guess I screwed up in this thread to, I wasn't paying attention to everest as I haven't cared nor accepted them as a company since they removed the home version...
But, the VRM seems to be causing some serious issues, and could end the end, it self fry if you don't take action now. The reference design of your card, had them heatsinked, and covered by the GPU/DRAM heatsink it self. BUT, manufactures like to cheap out on heatsinks on all parts, just like your GPU, motherboards have a set of VRM's for the processor, and a lot of ~$50 motherboards, even some higher end ones, don't have a heatsink on them, and these babys, get HOT...
But, here is a picture to help you find the VRM, just be carefull to not short out the contacts on them, use a non-conductive THERMAL PASTE GLUE, or THERMAL TAPE, I would go with thermal tape if I was new at adding small heatsinks like that, just because it's a safety type of deal...
VITEC = VRM chip,
http://resources.vr-zone.com/yantronic/1950pro/thermalpower/2phase.jpg
Atleast, I think it's the VRM, I know it's in circuit wit a transistor bank... Also, in that picture, are transistors, with a black piece covering them up, those I know for a fact get incredibly hot, and in the reference design, are covered by the main heatsink, but, it seems a lot of manufactures decided to safe ten cents and leave it off of those, so.
Also, here is the datasheets for your VITEC chip, note, it is designed to handle 125C,
http://www.viteccorp.com/data/af4268.pdf
Also, here is a good read on your GPU, seems the "non branded" version does have an issue with the chip I pointed out.
black screen after playing games for a while (Radeon X1950Pro) [Archive] - techPowerUp! Forums
Two things came up.
Power supply and the vItec chip peach pointed out.
Placing one of the spikey Zalman heatsinks on the vItec chip apparently worked.
So, if you can, get some copper zalman heatsinks with thermal tape, or if you have experience, and know for a fact that you wont leak/squeeze out thermal glue, get some high quality stuff from newegg and use that, but be warned, a lot of the times, you can short contacts out using thermal glue if it's conductive when cured, so look for non-conductive when cured and let it cure. You should then be set to go.
Get pure copper, no painted/silver or anything like that, you should use a pure copper heatsink with fins on it, and if possible, have a fan installed blowing air towards that card to help remove the heat.
BTW, once again, sorry for ignoring a previous picture, and for this long *** post.