I’ve already discussed using hdparm -t as a way of performing some elementary data throughput tests. But hdparm doesn’t test a broad range of I/O operations, nor does it test performance over long periods of time, on large and small files, or on filesystem metaoperations such as file creation and deletion. For that reason, I recommend downloading and familiarizing yourself with some other performance test suites.
The two programs that I recommend are bonnie++ (http://www.coker.com.au/bonnie++/) and tiobench (http://tiobench.sourceforge.net/). You can use either program to run a variety of throughput tests on both individual block devices, as well as arrays (software and hardware). I urge you to perform tests at each stage of array deployment and performance tuning to get a better idea of the overall effect of the various adjustments on your system performance.