I will share my experiences with you.  I am running 24 rigs with the same cards dual mining DCR and LBRY.  I use Claymore to set my control parameters and all my machines run 970W - 1030W and I am getting 170-175 Mh/s on each rig.  I run with cclock of 1160, mclock 2020 (doesn't seem to affect hashrate much but if set too high will result in cards going into open CL), cvddc of 870 and mvddc of 890.  If you want to get your power down, lower your mclock by 50 and then 100 and see if it affects your hash rate.  It most likely will not have a huge drop in performance, but you may see a reduction in power consumption.  Lowering the mvddc has a big impact on power reduction efforts as well, and you can play with that to understand power consumption over performance.  Also, running a powlim of -10 will get your power down as well with minimal reduction in performance.  I am using the uber straps mod'd bios and August 23rd block chain drivers.  I have to run ethi at 5 or below or the machines become unstable, and each machine has to be tweaked slightly to get it stable since no two machine act exactly the same.  Most of these machines run for weeks without issue and only get reset when I update the miner or change what coin I am mining.  I run DCR at 28 on the nitro+ 480s which seems to be the point that I get the max of both before it starts to slow down the ETH mining.  Hope that helps.

That's about right with what i'm pulling with 6x of my Asus Dual OC 580s dual-mining eth and dcr as well, at -dcri 25 hashing 178 Mh eth and 4500 Mh dcr.