Off topic, but please tell me you got 840 pros?
The normal version uses a different type of NAND, and is rather slow and unreliable - putting them in RAID 0 and thus doubling the failure chance seems like a bad idea.
SSDs also get faster, the larger they are, so I would highly recommend returning those SSDs if you can, and getting a 240GB Samsung 830, 840 pro, or OCZ Vertex 4. That way you get a reliable drive that's bloody fast without having to worry about RAID and if TRIM is enabled. (If your motherboard can't support TRIM in raid, then you should be running away from it fast - it means that you're killing your drives with every write... and doing so very quickly.)