What you saying?
If you have a only, oh lets said 1GB or somehow less ram on a 64bit OS, the fastest ssd and HDD will be bottlenecked by the system memory.
I recently upgraded a family friends computer ram recently due to booting up into windows was taking an over an half an hour. Yes half an hour and sometimes longer! Went from 512MB of ram and to 2GB of ram, the Os was loaded up under a minute.
So, the storage drive is not the most limiting factor but it's a common one.