Computer Systems: Processor and Motherboards/Buses

The options I have for processors are the intelcore i7-920 processor (8MB L3 cache, 2.66 Ghz) included in price, the intelcore i7-960 processor (8MB L3 Cache, 3.2 Ghz) add $470.00, the intelcore i7-975 processor Extreme Edition (8MB L3 Cache, 3.33 Ghz) add $900.00, and the intelcore i7-980x processor(12MB L3 Cache, 3.33 GHz) add $1,100.00. The main difference between the four processors is the Ghz of computing speed. I would select the cheapest one because it has ample speed.