Hay ya Bill
The "X" was supposed to be subjective, as in put whatever ya want in!
I for the life of me can't understand the low "267 Mb/s" you state through the Intel controller of your motherboard you stated as MAX , you might have a problem with your set-up as I had 440Mb/s on the ICH10R with 6 really old spin points raided on the same controller you stated.
And a new motherboard to get around the present bottleneck........Unless I've missed something , I don't know of any board on the market that can perform unmodified to a high end SSDs full potential......PCI-(*) has the bandwidth right now.........
You also might want to change supplier for your addon cards......I just not 6 weeks ago purchased a RocketRaid 640 6gb/s supported card for way less then half of what your stating...........infact if you only need 2 sata ports you can cut that in half again with the 622 card, again 6gb/s compliant.
Try and keep an open mind on Hybrid drives as it's not the black and white subject going off your rigid statement. I ordered and paid for 1 unit some months back and the silly buggers sent me 3! I can assure you from experience that they work no slower then any 7200rpm drive on the market and any program I have opened before, load quite a bit quicker,widows boots faster and a virus scan literally flies ! At about 16 pence a gig..........I think them very good value for money, but each to there own!
Aussie Allan