You need 2 separate RAID drives. RAID two 500 GB SSD's with Terminal, and install a live working OS. This requires a cloned copy of your working drive, the 2 SSD's in a RAID 0, and 2/ 2 slot (or a 4 slot) USB 3.0 Dock. This is the only way to install an OS on a RAID. For the scratch drive, I use 4 1TB 7200rpm drives , RAID all 4 together in Terminal. USB 3.0 will run at 5GB's. System bus is 6GB's. Your SSD RAID will do over 900 (BlackMagic), both read and write, but limited to real time 6GB's. 4, 7200rpm hard drives in RAID run 600 (BlackMagic), so 6GB's real time editing. You cannot edit 4K without a scratch disk. The standard hard drives help eliminate the SSD bottleneck.
