3DMark is a GPU/CPU benchmark used by PC gamers to measure system performance. Here are some great charts showing
My home computer system is very weak compared to these charts, except in one dimension, which is that my 1600 x 1200 display puts me in the top 10% of gamers. Woot!
While many people (myself included) have switched to laptops and/or all-in-ones, if you’re planning on building a new desktop, check out the Ars Technica system guide. The guide does a good job of speccing out a “Budget Box”, a “Hot Rod”, and a “God Box”, and it’s updated every quarter.