I'm asking this questiona specifically about the above machine, but I guess the answer could be generic across a lot of different applciations.
I have one of the above machines with a WD Blue 500GB drive (not the colour, the model..).
I want to use RAID 0, so am looking at getting another 500GB drive. If I bought the black edition with a 32MB cahche as opposed to the 16MB in the blue, would I have any problems, or would I get any gains?
I know this probably belongs on superuser, but its in beta and this could apply to someone building a server....
The software RAID/mirroring will work with different drives but it is likely to go at the speed of the slowest drive. In general identical drives are recommended.
The most obvious drawback is that you will lose all your data when any of your drives will fail. This is especially dangerous since the harddrive you mentioned is not certified for 24/7 usage.
Advantages (performance-wise) depend on your workload.
For almost every scenario the risks of RAID0 by far outweigh the benefits. If you need those disks for fast random access scrap data, look into a SSD.
RAID0 has a way higher probability of a non-recoverable failure than a single drive. If you want this as 'simple' storage, look into RAID5. Harddisks have never been cheaper.
With what Jan said about losing your data if one drive fails...
Although you lose your data now if one drive fails, with two drives you lose your data if either drive fails. So you basically are doubling (although probably not quite) the risk over just one drive with RAID 0.
Since there is this increased risk , I wouldn't mess around with RAID 0 of anything but the exact same drive, even though in theory it should work fine.