IOMeter is another open source synthetic benchmarking tool which is able to simulate the various loads placed on hard drive and solid state drive technology.
We use a custom Kitguru configuration for 4k random write to measure performance. We use the same test, but for random read performance also.
IOPS performance is actually very good, scoring over 43,000 in our 4k random write test. This drops to 24,661 in the 4k random read test.