I'm due a processor upgrade, my current is not able to keep up with games as well as I hope and it's my mightiest set-back. I'll list my current setup below:
CPU: AMD Athlon II X4 635
GPU:NVIDIA GeForce GT 440 1GB
Novatech PowerStation Gaming 600W Silent ATX2 Modular Power Supply
MOBO:FOXCONN A74ML 3.0/A74ML-K 3.0
RAM DR3 Dual-channel 2x2GB (Can't gather more info)
Hard Drive: Samsung HD502HJ 500 GB SATA Hard Disk Drive
My fans are all Stock.
You need a better graphics card not a better processor to improve gaming performance. A new CPU even an i5 3570K overclocked to 4.5GHz will not improve gaming performance by the smallest amount without a new graphics card.