Video rendering often requires drives with fast transfer rates. SSDs may not be the best choice, partly because of the cost/byte, partly because you wouldn't benefit that much from their very fast access times, and partly because their write transfer rate typically isn't stellar.
The Velociraptors are similar - they have fast access times, but don't particularly shine in terms of transfer rates.
To maximize transfer rates the best solution is probably to use two or more "black" drives in a RAID-0 volume. Be aware, though, that RAID brings it's own set of complications and RAID-0 in particular increases your chance of data loss.
Before resorting to RAID, you should make sure that your files are optimally placed. If you have your input and output files on the same physical drive, that can slow down performance quite a bit. Try putting your input and output files on separate physical drives, and if the renderer is using work files then put those on a third physical drive.
Note that putting files in two separate partitions on the same physical drive will NOT improve performance.