finally decided to raid 1 my data system as the current single drive (WD sata150 200g 8mb) is sounding clunky ... but I have a few questions. I plan on doing this in stages.. purchasing the raid 1 drives one at a time, pulling the old one when it fails or when I absolutely have to have the space. As well I want sata II's for when the system gives out probably in another two years or so. So, with that in mind I am looking to get a 320g drive that is sata II with 16mb (maxtor diamondmax 10) Does anyone know if differing memory combinations can hose things up? and what about the different sata types? the system itself is a few years old so it only will run sata150 (promise pdc20376 integrated on the MB) but as i understand it is required for sata300(ii) drives to backward compatible, right? so it shouldn't be a problem.. should it? * * * as for the upgrade process it is complicated as I have only two sata150 slots and while one works by itself, if there are two in place they only work in a raid configuration. So I put together a plan and then I talked to someone at promise and they thought it could be ok, albeit not ideal. the plan is when the 200g drive gives out to pull it, putting the new drive descibed above in its place. Next would be to put in a new backup disk (320g or more?) and set up the array again, resulting in two disk copies filling 200g of 320g. So then I would pull the backup, and most likely repartition it to 320g (no longer raid), put the two back in, set it to raid 1 mode so it would be up to 320g. appreciate anyones input.