Good? The only good I/O benchmark for Windows is the Intel iPeak/Rankdisk suite. But as that's not free and rather complicated to use, easier benchmarks proliferate. But most benchmarks are not that well suited to SSDs or RAID-arrays, giving wrong/meaningless scores in some cases.
However, HDTune Pro is pretty balanced. Its evaluation, but offers you Filesystem Benchmark and Random Access benchmark; the two basic numbers.