Hey, I've overclocked my athlon 4800 64 x2 from a stock of 2.5ghz to tipping 3ghz using the stock cooler and it's stable running an hour in prime 95 so far using the torture test. The problem is that the temps are high (59-61C) at full load using coretemp for readings.
Providing I probably won't be pushing it that hard would you guys consider it safe to run providing it remains stable?
I think it's absolutely fine with those temps. I have a Brisbane X2 5400+ running Prime95 SmallFTT over 65C@3.2ghz for 8hours. I lowered the clock down to 3ghz, and it's still ticking along just fine today. Typical usage won't get temps over 58C. My cooler is Zalman 9500a.
Stress test your overclock for an extended time and if it passes you should be fine.