I want to upgrade my d805, i have £120 max which is the best cpu to use? I was think of the Intel Pentium 4 945 Dual Core "LGA775 Presler" 3.4GHz or the Intel Core 2 DUO E6300 "LGA775 Allendale" 1.86GHz i have the Arctic Cooling Freezer 7 Pro CPU Cooler so a oem will be fine.