What's your watts per 1 MH/s averaged across all your rigs?
Mine wanders between 425W and 440W per 1 MHash/sec. yours sounds typical.
I'm at 490 W / MH incl 2 tower cases with lots of fans.Ron
I'm currently at 500W per 1 MHash/sec. I haven't done any video BIOS mods (yet).
Testing rig with two Sapphire 5850 and one XFX 7850 pulling about 1.0 MH/s at 470 watts.