Why anyone would imagine 1 RAID controller could handle that kind of throughput is beyond me. And why would you mix brands??? Not sure how you RAID across different branded cards and the MB ports. Doesn't sound like any RAID I know. RAID 0;0;0
3 8-port or 2 12 port 3Ware's would likely have kicked their ass. The 4 port 3Ware actually has the best PCI-E performance ratio, but you aren't likely to have enough slots for 6 of those.
Did you read some of the text at the end? They had to remove the second video card ???? and optical drives for testing to reach those numbers and to get the cards to initialize... And the dual power supplies were totally jury rigged...
And I only resemble that guy in the respect that it would be fun to do, but I would have used a real dual power supply server chassis/MB and researched the right controller configuration before building it.
And big woop. I've had two 10-12x256GB PATA RAIDs in my home servers for what, 4-5 years... and while they are stuck on a 32 bit PCI bus, what is the BFD about plugging 24 drives into a 24 port controller and testing it and not realizing it is going to under perform...