Here is another useful utility I have been using. It is called HDTune (I have been using the free version 2.55). HDTune is available from www.hdtune.com. There are two versions avail, a free version and a HDTune Pro version 3.50 with costs $34.95 currently. The free version is a bit limited but it will give you some good benchmarks for your hard disks.
The interface is very simple and consists of a few tabs. To test your hard drive you simple select it from the list and press the start button. It will take a few minutes and return with some statistics on drive speeds.
HDTune also has the ability to run an error scan on the disk as well as give detailed disk information.
I found one small issue so far. I have one system with an external sata disk array with 4 x 500GB sata disks. Two of the sata disks are currently configured as a stripe set. HDTune was able to test the single sata disks but could not test the Windows drive letter that was using the two striped sata disks.
I have used this util to compare several disks throughput. Please post any comments if you also use this good util.