Price is the key selling point for most PC buyers, but for the speed-hungry, only computers with the fastest microprocessor will do.
Processor performance is measured using benchmarks, of which there are many, used to gauge how a chip will perform when running operating systems, games or other programs.
Chip giant Intel, which settled a class-action lawsuit last year after posting 'defective' benchmarks, is trying to push the message that newer classes of processors need to be measured differently.
A benchmark frequently used as the basis for computer magazine reviews is Winstone.
It is an application benchmark, meaning the chip's performance is tested while the PC is running a common software application such as Microsoft Word or Excel.
Some others, such as the CPUmark and Intel's own Media Benchmark, are synthetic benchmarks that measure performance using simulated application program functions.