Can you tell relative speed differences of CPU's via benchmarks

[jamoost]

With processor benchmark tests and results can you determine how much faster a CPU is than another CPU? For example if AMD Athlon II Dual-Core M340 passmark CPU is 1266 and compared to the Intel Core i3 380M @ 2.53GHz passmark CPU score of 2316 could you say the core i3 is 83% faster? if not is there a test that you could reliably quote relative speed differences between CPU's?

[David (PassMark)]

Yes, the i3 is 83% faster for the operations performed in the CPU benchmark.

But in real life the difference in system performance will be smaller because of factors like,
1) Not all software using all available CPUs (i.e. the software is single threaded)
2) Other system components being a bottleneck (e.g. the disk being too slow to keep up with the CPU).