That certainly doesn't look right to me. I haven't tried HD Tune but I would have though you'd see numbers closer to this:
http://thessdreview.com/our-reviews/ocz-vertex-3-240gb-sata-3-ssd-review-hdtune-pro-benchmark/
Check it's on AHCI mode in the BIOS and that you've got the latest Intel Rapid Storage Technology drivers installed.
There's your problem. The Marvel SATA3 controller is rubbish. You need to use the Intel SATA3 ports only to get the benefit from very fast SSDs.
You're going to have to move your RAID to either the Intel SATA2 ports or the Marvel SATA3 ports.