Use this link to find the best Core 2 Quad for the money (probably the Q9550), that your motherboard will support according to the Pegatron 2A84h motherboard CPU compatibility list.
https://www.cpubenchmark.net/socketType.html#id5
The number to the right of the colored bar is the Benchmark CPU Mark, and higher is better.
Processor Support Pegatron Corporation 2A84H Mainboard Intel Socket LGA775
http://www.findlaptopdriver.com/pegatron-corporation-2a84h-motherboard-rev-1-03-specs/
Check Intel Core2 Duo/Quad CPUs offered here.
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2322090.m570.l1313.TR0.TRC0.H0.Xinel+core+2+duo%2Fquad.TRS0&_nkw=inel+core+2+duo%2Fquad&_sacat=0...