How much IO can we push to 5 SATA drives?

It was not a fun day, with a glitch on a fiber channel link causing corruption in an Exchange database. As a side effect of recovery we've stress tested the SAN a bit. Note this is captured at 12:45am local time (so general activity is lower). Plus we've removed non-essential load to keep performance up, and rebalanced some IO off the 5 SATA volumes back to FC. Apparently the pressure reports need more watching... At least these drives are SATA-II.