It's been a long time, and I can't recall anymore. I thought a Z-class motherboard was required for IRST, but I'm finding conflicting information when I search.
Also, I find the IRST download available on the B85 motherboard's website.
OK. That's what I figured. I think I got Rapid Storage Technology confused with Intel Rapid Start Technology, which I think it does support. Thanks for waking me up.