The price for a 160 Gbyte disk will be around USD 15'000. This is still a bit expensive. But the access time is around 0.5 ms (both for reading and writing) which is around 10 times faster than a normal 15'000 rpm SCSI disk! The disk has NO cache because it is a cache itself (according to the supplier. Maybe this will change in the future). And the lifetime of a cell is > 5 mio writes. For the same performance one needs usually an array of around 10 disks. If your database is heavily write-I/O bound you should consider this solution.