Capacity & price:
The OCZ Revodrive 3 x2 240GB SSD is less than 25% of the capacity of the Western Digital VelociRaptor 1TB HDD but costs about twice as much. So the SSD storage is roughly 8 times as expensive.
SSD 1520MB/s, HDD 200MB/s – SSD is roughly 7.6 times as fast.
SSD 1129MB/s, HDD 200MB/s – SSD is roughly 5.6 times as fast.