keep in mind you´ll need a dedicated SATA raid controller to get the full bandwith on the striped SSDs.
1. Samsung 840 EVO 250GB (OS and programs)
Wish it had been a 840 Pro, not the EVO.
2. 2 x Samsung 840 EVO 500GB Raid 0 (about 1000Mb/s read and write)
That is very optimistic. EVO is lousy in writes and there are not enough SATA 6G Intel ports on most motherboards to achieve that transfer rate, even with Pro SSD's, let alone the relatively slow EVO.
3. Samsung 840 EVO 500 GB (I can use this if I want/need)
On what port do you intend to connect that?
4. 2 x 2tb Caviar Black (I can use this if I want/need)
Could very well be connected to SATA 3G ports for media and projects in (r)aid0.
5. A bunch of small SSDs and other HDDs.
For whatever you need/like.
6. Drobo 19TB for storage and safe keeping.
Great for backups, too slow for anything else.
2 x EVO in Raid 0. I already have around 1000mb/s and I'm relatively happy with that performance. I can buy a RAID-controller for these.
But what should I use them for? Maybe put them in Raid 3 with the last EVO?
The question is more like:
How would you set up the ideal hard drive configuration based on the drives I have?
I'm running benchmarks and getting 1000mb/s.
Maybe not real life performance, but faster than single drive.
Any controllers you recommend?