Answer

You can check your RAID 0 Stripe size in INTEL IRST Option ROM utility screen, if Stripe size value is 32KB or lower, you can set it to 128KB to improve SSD Read speed. On the other side, depends on the default of different HDD benchmark utility, the scores would be variant. Please adjust RAID setting by your actual requirement.

Also please be noticed that before you do any change in RAID setup, the action of system data backup to external storage device is required, otherwiese the whole HDD data will be destroyed. If you just need to have a OS restore DVD without backup old data, you can use msi burn recovery to build a recovery DVD.
For more details of RAID settings and backup procedure, please refer to SOP of "Super RAID perfromance fine tune_rev.pdf"