Using RAID to mirror your system drive might seem like a good idea, but it's really not. It's true, you'll have a backup if one dies... but that's what backups are for. If the system crashes, then the machine needs to be rebooted, and your RAID might be out of sync for important files such as the registry data -suddenly you're in a world of pain as the system tries to not only make sense of two disparate files, but at the same time trying to resynchronize your array. Also, using the RAID for your swap file is NEVER EVER a good idea. Each time you write data to it, you need to write twice, and it will slow down the use of the swap. The swap space should, if possible, be on its own drive/partition, and if possible not the system drive if you use a partition for it. The swap file should be considered something that goes away when you reboot - not something that you need to protect by using a RAID mirror.