Have been playing with RAID on the DG45ID in the last couple of days. Board is confirmed to be lated FW (117), Latest Intel Matrix software (8.9). Had the same configuration of 3x500G WD Hard Drives running as RAID 5 on an HP desktop.
For some reason, the combination of this MOBO, RAID 5 or 1 and Win 7 64bit ( did not try anything else) results in very low performance. Copying large files to the RAID volume either from antoher HD or from the LAN results in 1.5Mbit/s trasfer speed. Same PC, copying from the LAN to the HD that is out of the RAID provides 10Mbit/s (LAN speed...).