Latency and random IO is the key
He's right, it's the random IO rate and latency that are the key benefits of SSDs. Bandwidth is easy, you can always buy more width. IO rates you can increase by buying more mechs. But no amount of purchasing mechanical disk drives is ever going to effect the latency times for data access. Apart from massively over provisioning storage so that you only make tiny head movements. But even if you get to the point where you have so many disk drives that you are only using 1 track on each of them you still have a 2ms average latency time on a 15K rpm disk. Using twin head towers you could get down to 1ms.
With SSDs you are in a totally different ball park.
