I recently came into possession of a 1TB Samsung Hard Drive

It's amazing, and having loads of space is awesome, but i know what slows most PCs down is the Hard Drive.

My question is, is it possible to RAID my OS Hard Drive, a 500GB Western Digital drive with my 1TB one, but split into two partitions?

so i have

(500GB hard drive 1) + 500GB partition (hard drive 2)

and the rest of HDD 2 extra?

is it also safe to partition a RAID system?

and what kind of performance gains would i get?

i have never used RAID before ^^"