Is it my fault!!

You might want to delete the other thread with the same exact post in it.

Im pretty sure you have to flash the bios to OC the 7800. There are quite a few good threads on how to do it floating around here somewhere.

It depends on your particular chip. Some go higher, some don't.

I take it you're using NiBiTor? Did you select a different VID mode (0-7) and not just a label (1.2V, 1.21V, w/e). It was pointed out a while ago that the VID keys control the voltage and that the voltage labels are just that, labels. Read the directions on volt modding and you'll see what I mean. Good luck and post back if you have any questions .

Aye, you may need to go to 1.3 but in your case it may be pushing it, if you have topped out at 375 at 1.2volts. Remember that even these gpu's suffer the same manufacturing process that regular cpus do. There are better gpus in a wafer and worse ones, usually due to the process of making them, the chips created in the center tend to be better performing than the outer groups. You may have one of those chips. I would say go the safe route with that one you have if you cannot go above 375 at 1.2 then it would not be worth it to go higher. You will just eat up more juice and create unneeded heat.

if you can do 350mhz core and 900mhz mem you will be alright.

Stock from Dell that card only does 250c 650m roughly only 20GB of bandwidth, you are getting if you do the above 28GB which is a good jump. getting 40% increase in performance and shouldnt knock it at all.

for comparison my 7800 I have not maxed yet, that is to say I havent taken it up till I got artifacts yet. So far I have run it at 430Mhz core 945Mhz mem @ 1.2 volts and got up to 80 degrees. I have every reason to believe I could push it more because I have no hit the cap yet, and I think that this chip may be a better one. But I cannot expect that if I ever replace it that I will get the same performance from a new one. Its a crapshoot.