Raid 1 with USB-discs
 

I'm currently trying to get USB-harddrives with Raid-1 to work properly but I got a couple of questions regarding this.

I failed one of the discs on purpose to be sure that the raid controller worked properly, this worked fine, but now when I'm starting the raidcontroller it want's to resync the whole disc again and since it 250 GB it takes a lot of time since it's only working in 20 MB/sec, is there some kind of patch that can identify which blocks that need to be resynced so it don't have to take 3 hours each time i want to resync from a disc-failure?

You/the computer is probably using mdadm for the sync process, AFAIK, it does what you're looking for. I takes a fair amount of time on my RAID connected direct to the MB, so it doesn't sound to unreasonable going through USB. Just the nature of the beast. Each to their own, but I wouldn't put RAID on USB.