C2Ds are awsome chips, i've got the E6850 3.00 that ive overclocked to 3.5 24/7 stable, idle at 30C, load 57C, stock intel cooler + 120mm Tt exhasust fan.
Why are you looking for a new processor? wnat more performance? Make sure its not your graphics card bottlenecking the CPU.
If not, just overclock that thing using the BIOS. Make sure you have Orthos stress test and realtemp temperature monitor program. try to keep it under 60-65. you can get it to 2.5-2.6 no problem with some patience.
Also try overclocking the graphics card using Evga Precision (if its nvidia) or Ati Tool (if its ATI), try not to go more than 70C on the graphics card, but its not dangerous until 90C+
Hope this helps
Jack
Happy to ask any of your questions
