Create an objective way to measure the performance of your computer system. By benchmarking your machine, you determine whether or not your tweaks and upgrades help or harm system performance. You can also use benchmarks to compare your system's performance to the latest and greatest products out there.
Graphics cards are a case in point.
But benchmarks can reveal just how fast that card is compared to the other cards you might want to purchase. Hardly, but gaming benchmarks, primarily with 3D accelerators, do seem to have a high profile. In terms of sheer numbers, Winstone is probably the most-used benchmark, built as it is around the most popular business applications. Sure, Winstone will tell you that your system runs faster. But running a benchmark based on Quake III will let you know just how much faster your favorite game runs.