Hi Bachus
SSD are more expensive then ordinary hard disks and a lot faster, (Hence the smaller capacity fitted) as an example in a recent test 1 SSD when tested was found to be faster then Twin Raptors (10.000 RPM) in a Raid Array.
Don’t confuse the modern SSD with the old limited capacity SSD in hardware arrangers.
If you don’t believe me, do a search for tests on the latest SSD. (And be prepared for a shock)
Regards

Bill