Rob asked me to fill in here, so here goes for my first post.
If i put any more than 2.5 volts in whatever the timings are at it errors.
hmm, i've seen some people have this issue before. a few questions that could help:
which bios are you using? i recommend bios 5/10 -2 for the dfi nf4 if you don't have an X2.
next.. which ram slots are you using?
in the bios, did you change the dram drive strength?
last, do you have a fan blowing on the ram? in my own testing i find that ballistix runs rather hot. while it's strange that you have to drop to 2.5v, cooler temps never hurt anything.
I read somewhere somebody got 2.5-2-2-5 @ddr500 with this ram.
this is an above average result, but is doable for some with enough voltage, proper tweaking, and good cooling.
What settings would u recommend for testing cpu stability in prime95, any other progs i should use?
settings.. i won't touch on, but for testing ram stability, i highly recomment memtest86
edit: just noticed that you said CPU
stability. silly me. use in-place FFT's in prime95
lastly, here's where you should enter your sig: