I've upgraded my PC to a 'Barebones' system from Novatech. It has an Intel Core i7 2600K processor (eight cores @ 3.40GHz each), ASUS P8P67 Motherboard, 8G of RAM and 128Gb SSD drive by Crucial (Solid State Drive, no moving parts). The OS is now Windows 7 64bit. So it can take full advantage of all the memory. I also have a 1Tb HDD for data. (along with countless others with data that get plugged in as and when).
This machine is incredibly fast. The processor is on of the highest speed processors on the market along with the SSD drive.
In theory the processor can be over-clocked to 5Ghz/core.