The Background: I have a D-Link DNS-323 (2-bay network attached storage device) that's currently got a couple of smallish drives in it, set up as standalone storage. I am looking to buy a pair of 1.5 TB drives (Seagate Barracudas, if that matters) to replace the two in there now, and set it up as a RAID 1 striped system so I have some redundancy.
The NAS is used primarily as networked storage, storing mostly media files. It also contains a shared iTunes library that several clients connect to independently (meaning iTunes uses the iTunes Library file on the NAS as its library file) and very occasionally serves as a uPnP iTunes server. It also runs a bittorrent client occasionally.
My Question: For the usage described above, how much difference will the gap between 5900 and 7200 RPM spindle speeds make?