Yes, a SSD with your OS an fast harddisk where you copy the whole bluray to. And one additional harddisk to where you transcode your bluray from the other harddisk can increase the speed of transcoding.
Because the harddisks with the mobies only need to jump to one spot at the time.
Not like if your using one harddisk it jumps arround on the same harddisk to read and write.
The way with 3 harddisks, depending on speed of sata, cache of harddisk, can speed up the process by factor 2. For example you have the same movie rendering it on same harddisk with a speed of 70MB per second. If you use above mentioned method it can increase to 150MB per second. (the values are for DVD). But even for BluRay it can increase.
Its not only the CPU.
CUDA, Quicksync, AMD whatever, will speed up the rendering but for a price of quality loss.
If I have time I may post a comparison of using one hd to read and write and two hd, one read the other write.