I just replaced father's CPU AMD SEMPRON 2600+ 754 with an AMD ATHLON 64 3000+ 754 on a GA-k8ns using the STOCK COOLER.
But the temps are very high according to the ridiculisly looking GIGABYTE utility. On load they reach 61C. So I looked at AMD site and there they say that the STOCK 754 COOLER is good enough for all of their 754CPUs. So I took out the CPU and reapplied the thermal grease but nothing helps.
I also tried it with SPEEDFAN which gave me even higher CORE temperatures. Could the readings be wrong?