3 Harddrives - RAID 0 or something else?

So I have 3 hard drives:
2 Seagate 7200RPMs with 16mb cache...I believe the latency is around 8.9ms?
and 1 Samsung 7200RPMs with 16mb cache with seek time around 7.2ms?
Both with latency around 4.6-5.0.

Should I keep my current configuration - 2 seagates in RAID0 (main drive with OS) + 1 samsung in non-RAID backup...or would it just be faster to use the 1 Samsung as my main drive and use the 2 seagates as my storage/backup?

I usually move files <100megabytes, and I've heard RAID is not good for file transfer in small chunks.