First of all, the AS SSD screenshot is telling you that the alignment of your OS installation is wrong, the "31 K Bad" entry. That is causing poor performance from your SSDs, particularly in write performance. I assume you put the OS on your RAID 0 volume from a backup image? That is causing the alignment problem.
Do you have Write back cache enabled in the IRST UI in Windows? That will improve the write performance too.
Frankly, I have scored better in AS SSD with one 120GB SSD on a SATA II port, than your results. The alignment problem is the main thing needing fixing, and then enabling Write back cache.