I have decided to set up a Raid 1 array, probably with two 1TB drives. I'm also considering a raid 0 array for my os/apps drive to increase performance.
My question is, do I need to get a raid controller card to do this? If it is not required, is it recommended? Does it depend on the type of motherboard? I've never tried to set up this type of configuration before.
Some motherboards have a chipset that let you create RAID arrays with the help of a special disk driver which is loaded by the operating system. For example, boards that include the Intel ICH10 chipset have this capability, and when you install a recent OS such as Vista or Windows 7, the install disk detects the chipset and automatically loads the RAID drivers for you.
Look for the documentation for your system or motherboard for information as to whether your computer has this capability.
Be aware that RAID 0 doubles your chance of loosing data due to a disk failure, so its important to have a backup strategy (actually, it's ALWAYS important to have a backup strategy, even with RAID 1, because of all the risks to your data that RAID cannot protect against).
You should not need to buy any seperate controller if you wish to use RAID0/RAID1. The onboard ICHxR controller is often faster than hardware RAID configs thanks to RAM writeback.
Never use RAID to enhance the reliability of your data; only do this is you *truely* know what you are doing, or do as i recommend and focus on keeping proper backups instead. This will protect you against much more dangers than RAID ever can, including filesystem corruption.
RAID is not a backup. Lets all say this together, "RAID is not a good way to back up my files. If I use a RAID array as a backup, I am most likely at some point going to lose all my files." This is not opinion, this is a fact.
But, to find out if a board supports a certain type of RAID configuration, you have look at the specs. Many boards do support RAID, but they do not always support all types of arrays, be sure to read the fine print under the controller specs to see what kind of arrays the controller will support!
Thanks for the info everyone, I'll go with an external drive to back up my most important data. I'm curious though, what is the point of Raid 1 if not to protect yourself from data loss?
The purpose of RAID 1 is not to protect data, it's to minimize downtime. In a server environment, a disk failure takes the server offline and results in dozens or hundreds of workers who can't do their jobs. That's what RAID 1 prevents. But it doesn't prevent those same workers from accidentally deleting their files (or many other risks to data) - that's what backups are for.
A backup protect against everything a RAID protects against, and much more. That's why having a backup is superior to having a single redundant array. And since RAID1 and a backup cost as much additional space, there is little reason to pick RAID1 over the backup if data-loss is your only concern and up-time is not important, as for mostly all consumers.
Always have a backup for things you don't want to loose, RAIDs themselves can fail, even with 100% perfectly fine disks. In fact, adding RAID to your storage system makes it more fragile as you're adding a single-point-of-failure to the system; no matter how much redundancy, if the RAID engine itself fails in some way you may still be affected by data-loss.