How Many GHz Should a Desktop Computer Have?by Casey Labine
The More, the Merrier
Unlike laptops, desktop computers don't run on batteries, so there's no such thing as too much processing power. Regardless of what it will be used for, more GHz (short for gigahertz) means a faster and more responsive computer and, by extension, a happier user.
GHz Isn't Everything
Since multicore processors appeared on the scene, raw GHz hasn't meant as much as it once did. Intel's Core i7-920, for example, runs at 2.66GHz, yet is significantly more powerful than the older Core 2 Quad Q6600, which runs at 3.7GHz---a full 1.04Ghz faster.
A processor with more GHz isn't necessarily faster, and how fast a processor a particular desktop computer needs really depends on how that computer is going to be used. For word processing, web browsing and other basic functions, any 2GHz processor will do. For graphics-intensive gaming or other 3-D software, 3 to 4Ghz is more appropriate.