luzhun :
Hello. I am already using 2 SSD's in Raid 0
Outside from a couple very specialized use cases, RAID 0 on SSDs is pointless. SSDs are so fast that if you RAID 0 them, your performance with small file read/writes (which are the operations which bottleneck HDDs and SSDs) will probably
decrease due to adding the overhead of RAID.
Read through the real-world test results with two SSDs in RAID 0. While the benchmarks are fantastic, real-world results yield little improvement, or a decrease in performance.
http://www.tomshardware.com/reviews/ssd-raid-benchmark,3485-10.html
The specialized use cases are real-time video editing, and if you frequently have to copy large files from one SSD to another.
, but am planning on buying 2 more of the same exact ones so that I can get the backup capability in case one of the drives fail.
RAID is not a backup. RAID is for redundancy - if a drive fails, your data is still accessible and you can keep working. Whereas without RAID, you're stuck waiting until you can get a replacement drive and restore from a backup.
Even if you have RAID, you still need a backup to recover from things like accidental file deletion or overwrite, ransomware encrypting your files, or loss of your computer due to fire, theft, or flood.
I already have Win 7 installed on the Raid 0 setup. When I do install the two other drives, would I need to reinstall the operating system again? or can I bypass that by going through BIOS?
If you've got the OS installed on the RAID 0, yes you'll need to reinstall again. But as I stated above, there is very little point to having RAID 0 on SSDs. And putting the OS on RAID 0 (or even RAID 5) is just inviting a lot of headaches in the event of a hardware failure.
You are much better off using one SSD as a boot drive, the second SSD as your frequently-accessed data drive, a large HDD as your archive drive (can be a SSD if you're made of money), and an external HDD for backups which you leave in your desk at work in between backups (in case your house burns down).
Edit: And no, there's no way to convert RAID 0 to RAID 5. RAID 0 is just your data spread across 2 drives. RAID 5 is your data split up with a piece stored on each drive, with one drive holding parity data.