Hey!
I have 8x Sapphire Nitro+ cards. I do get that the cards do consume even when not minining. I do have the TPLink-HS110 smart plug and the Kasa app on my iphone. When no cards are plugged and system is on, it pulls 53w. When I have all 8 cards dual-mining, it's pulling around 1240-1260w at the wall.
(1260-53)/8 = 150.875w per card.
I have both cvddc and mvddc set at 875mV and as per HWinfo, they average from 850 to 865mV when running.
If you want to consume less, try lowering your dcri value from 30 to 25 like mine. It'll lessens your dcr hashrate but should save you around 5-8 watts per card.
I have posted it beforeI was unlucky enough to buy the TPLink-HS100 and not the HS110 model (actually the HS110 didn't exist in my country at the time). I am considering buying it now, even though I am currently using a borrowed
Ubiquiti mPower (EU) which I have found to be pretty accurate.
My idle system consumption is 35w and total consumption while Dual mining is 1307, so it is 159w/gpu. Reducing dcri is the only thing that I haven't tried yet, I will do so in the next days and let you know, thanks for the tip.