just switched to 1.3n5 and found a decrease of 40w across the rig with no drop is hashrate. amazeballs!
Very interesting. I upgraded also and actually saw zero drop in wattage on my 8-card rig. I know, I know, it's because i'm using Win10!

Which version did you switch from?
dunno been afk a couple of days and it was running on mmpOS.