I've discovered the hard way that RS2WC080 controllers don't detect SATA hard drives set to "power on in standby", let alone try to spin them up.
This occurs whether the drives are directly connnected or via a SAS expander and on all versions of firmware tested (the last 4 Intel revisions plus LSI's latest version which hasn't been released by Intel yet)
The drives in question are Samsung "green" F5 units - model HD204UI
I haven't confirmed if this occurs with other brands, as I don't have any to hand.
Can anyone else confirm? if so it's a serious bug given that I bought the card with staggered startup in mind.
The RS2WC080 supports staggered spin-up. See the features list on page 2 of the http://www.intel.com/support/motherboards/server/sb/CS-031251.htm Technical Product Specification. You might be able to find other information you're looking for in that document too.
For HDD compatibility, see the http://www.intel.com/support/motherboards/server/sb/CS-031393.htm Tested Hardware & Operating Systems List for the RS2WC080.