For free storage device benchmarking software, I highly recommend CrystalDiskMark. The interface is nice, clean, and simple to use. And the results are easy to understand!
You can even record the test results by pressing Alt-PrintScreen (after the benchmarks have completed, of course) to post to your website or blog for sharing and historical comparisons.
I’ll be using this program in my next blog post to test VeraCrypt’s (a free storage device encryption program) performance vs the same plain hard drive.