The best tool for comparing CPUs.

I've mentioned this before, but in my opinion, this is the easiest, best site for comparing CPUs: PassMark's CPU Benchmark. If you want comprehensive tests, then I suggest Notebookcheck.net's list of (mostly) mobile processors.

Below, is an abridged portion from Passmark's ranking of the best CPUs.  Highlighted in red are two of the least expensive desktop options: Intel's $315 Core i7-2600K, a 4-core Sandy Bridge CPU at 3.4Ghz (boost speed at 3.8Ghz) for desktops, and AMD's $267 Bulldozer FX-8150, an 8-core CPU running at 3.6Ghz.  Notice how the 4-core / 8 thread CPU outperforms the 8-core / 4 module CPU.

Some other things worth noting: the Core i7-995X and Xeon W3690 are both 6-core CPUs (and are actually very similar inside); the Core i7-2960XM is a second generation mobile CPU, the top of the line mobile.

I have a laptop running an i7-2720QM; by comparison, 2010's top mainstream mobile processor, i7-820QM is much slower, and much more expensive than the second generation i7 CPUs.  You can see why I jumped on a refurbished Dell 17.3" laptop running i7-2720QM, for $825.

Core i7-995X	10945
Xeon-W3690	10227
Core i7-2600K	9971
Core i7-2960XM	9084
AMD FX-8150	8681
Core i7-2720QM	7,123
Core i7-820QM	3,557