Bottlenecking is more of a theory. It is the slowest part of the PC, that impacts performance of a newer, better part. i.e. Using 8800GTX with a Celeron. Usually the biggest bottleneck is the hard drive, but many say it's the CPU.
Also, there are no programs. You can use 3DMark to see the CPU score, and the 3D score, but the benchmark isn't that great in telling real gaming performance.