IMO the X2 overclocks very well. It just depends on what you consider good. I'm running my 4200+ (normally 2.2GHz) at 2460MHz 24/7 running SETI on both cores with 100% utilization. At this speed it runs as fast as a stock 4800+ which costs nearly twice as much, so I consider that good.Originally Posted by arthurleung
The X2's are much harder to overclock than the San Diego and Venice chips. My 3700+ San Diego (also runs 2.2GHz stock) is happy as can be running 2830MHz on the same air cooling with less volts than the X2. When overclocking the X2 you need lots of volts because you are overclocking 2 AMD64 CPUs at once. You also need very good cooling.
I'm probably going to water cool the 4200+ SETI box to see if i can get closer to 2600MHz 24/7. I'm not a big fan of water but it is necessary for high X2 overclocks. Most will have trouble running more than 200MHz over stock speeds on an X2 without very good cooling.