Drive Setup for DAW

Hi all,



I know this has been asked before, probably numerous times, but most threads seem to be from 2011 or 2009 when SSD's weren't the norm (at least in the "normal" computing world).



What's the preferred setup for a DAW? I was originally thinking:

-SSD (256GB) for OS and programs

-7200RPM (2TB) For samples and projects (video and audio, video being playthroughs and the like, probably shorter clips)

-7200RPM (2TB) For backup



But some input has me re-thinking.



As far as I understand (correct me if I'm wrong), the purpose of splitting them up is for "optimal" reading of the drives, which is why you want samples and audio projects split up.



I'm wondering now, though, how to change it up without increasing costs (if possible). I'm also wondering how big a drive one would use for samples - i.e. EW's Ghostwriter was about 70GB (that's just one library).



Would something like this be more than enough?:

-SSD (128GB) for OS and programs

-10k RPM Raptor drive (300GB) for samples

-7200RPM (2TB) for audio and video

-7200RPM/5400RPM External HDD (1TB for now, increasing with time) for backups.

Drive Setup for DAW