so i guess i can use either to store stuff,it might be best if i evenly use them!
Personally, I've always run at least two drives. The second drive always has a basic bootable opsys plus is used for quick and easy bak-ups. If I suffer a problem with my primary I can boot my secondary straight away. In addition I have an external third drive for more secure bak-ups.
There is nothing worse than losing a drive, going for a bak-up and finding that's got a problem too. My philosophy is not just make sure you have a bak-up but also bak-up your bak-up.