Prime95 ERROR help

[Toad Boy]

I've overclocked Phenom ii x4 965 to 4Ghz, just with multiplier and ratio.

In the first core I got 'FATAL ERROR: Rounding was 0.9414550781, expected less than 0.4. But the other cores were fine and carried on testing.

Could this be because I didn't change the voltage?

Or is this not a significant problem?

 

[PaulyD]

Needs more voltage. Any error is an unstable overclock in Prime95

 

[NoNameNoNumber]

More V although currently when I get past 3.8GHz on my 955 I cannot get any further regardless of how much juice I give it :/