In the latest version of RST, the SRT function won't allow you to pick a raid drive to accelerate with an ssd. I assume this is a bug as i've not been able to find any reason as to why you wouldn't be able to do so.
I have a spare 60gb ssd laying around. And figured i'd use it to accelerate my drives instead of letting it collect dust.
My drive setup is
C: ssd
D: 500gb hd
E: 2x sshd in raid0
I obviously don't need to accelerate my C:. But my 3 mechanical drives on the other hand. What i wanted to do, using 41.1gb to accelerate the E drive, and 14.9gb to accelerate the D drive. If i could i would've split it 50/6. But 14.9gb is the least you need to assign.