Question about AT7-MAX2, RAID, and SATA

Greetings,

Right now I have 4 UDMA-100 drives hooked up in a 0+1 configuration. I
am looking to move this over to 4 SATA drives for the increased cache
speed (specifically the Hitachi drives after you switch them from
quiet to performance mode).

My question is in my HPT raid configurator it looks like I have 4
channels. Two are the IDE channels I know, because that is what I have
my 4 drives hooked up to. I was wonder if the other two channels are
the SATA channels (it is unclear to me) and if I can get two drives
per channel like I did in the IDE configuraiton (when I boot up, I see
the listing for 8 drive slots in the RAID BIOS, and I am currently
only occupying 4 of them).

Please no "this is such an obvious thing you moron" posts, because if
it were that obvious I wouldn't be asking. I am new to SATA and don't
want to make any mistakes buying stuff I can't use.

Thanks!
Dan