I'd say exports can go to the slowest drive, don't really need ssd for those.
- Intel SATA 6G: OS+Programs+Pagefile: SSD 256GB (I already have this)
- Intel SATA 6G: Media Cache: SSD 120GB, but too small
- Marvell SATA 6G: Projects: SSD 120GB, smallish and only 350 MB/s
- Marvell SATA 6G: Preview + Exports: SSD 256GB, only 350 MB/s
- Intel SATA 3G: Media files: HD 2x2TB in RAID 0
- Backup: External e-SATA HHDs
...be aware that the new Haswell E, ( enthusiast) CPU is coming out later this year.....if you can hold out until the 4th quarter of 2014....you may want to wait.....the new features and performance increase will BE SIGNIFICANT !!! Up to 8 physical cores, (16 theads), Quad channel system memory, on board PCI generation 3, larger caches, and a new chipset allowing ten 6Gb/sec. SATA III ports to be on the motherboard. THAT is what I AM doing !!!!....WAITING for that......the 4930K is tied to the "old" technology of only two 6Gb/sec. SATA III ports and a slower memory system and motherboard. You may have more high speed storage options with this new chip and MOBO... WITHOUT having to go to an expensive RAID solution !!! Maybe the NVidia 780ti will be ON SALE by then !!!