Would like information about idle power consumption with dual monitors

[frozentundra123456]

Hi everyone

I currently am running dual monitors with a HD7770. The monitors are on the majority of the day, but at idle a lot of the time. I would like some information if available about idle power consumption with dual monitors on the HD7770 vs the new generation Polaris and Pascal cards. I seem to recall seeing some information that the new nVidia cards are very efficient under dual monitors, but am not sure if this is correct.

And please, this is a simple question asking for data on dual monitor idle power. I am knowledgeable about the rest of the performance of the newer cards, but power consumption *is* important to me. Please none of the usual "power consumption doesnt matter", "switch to LEDs", "you only same a few cents a month" comments, and lets not let this degenerate into the usual Red vs Green arguments.

 

[tracerit]

I have a RX 470 and dual monitors. With two or three monitors connected to my RX 470, the memory clock speed is always at max, thereby adding +25W on idle... which totally sucks. So now I have to connect my non gaming monitor and my TV to onboard so only my 144hz monitor is connected to the RX 470, thereby idling lower. I also have to run my 144hz monitor at 120hz, otherwise the memory clock is maxed out as well. Sucks.

 

[frozentundra123456]

I have a RX 470 and dual monitors. With two or three monitors connected to my RX 470, the memory clock speed is always at max, thereby adding +25W on idle... which totally sucks. So now I have to connect my non gaming monitor and my TV to onboard so only my 144hz monitor is connected to the RX 470, thereby idling lower. I also have to run my 144hz monitor at 120hz, otherwise the memory clock is maxed out as well. Sucks.

Yea, I though there was some bug with the new AMD cards that caused high idle consumption with dual monitors, but I thought maybe they had fixed it with a driver update by now. My 7770 does downclock at idle, so maybe it is not too bad. The price and performance of the 470 is really good right now, but with my dual monitors, I would be very reluctant to buy the card if it doesnt downclock properly at idle.

 

[Borealis7]

TPU does multi monitor power consumption charts in every one of their VGA card reviews:

they describe their test:
"Multi-monitor: Two monitors are connected to the tested card, and both use different display timings. Windows 10 is sitting at the desktop (1920x1080+1280x1024) with all windows closed and drivers installed. The card is left to warm up in idle mode until power draw is stable. When using two identical monitors with the same timings and resolution, power consumption will be lower. Our test represents the usage model of many productivity users who have one big screen and a small monitor on the side."

and as you can see, nVidia is miles ahead of AMD in this area. i think this trend started with the HD7XXX generation, suddenly AMD's idle power started going in in multi-monitor due to higher clock rates they needed to feed both monitors.

so even side-grading your HD7770 to a cheapo used GTX660 or similar could save you on power consumption while not costing you much if you sell your card.

 

[Bacon1]

AMD uses more power until 3 monitors when Nvidia also clocks higher and thus uses more power as well. Fury (HBM) uses the least amount of power @ 3+ monitors since it doesn't use much power.

 

[Piroko]

I had a very similar setup in the past. What I can say is that both AMD and Nvidia cards will increase their core and memory clocks as soon as they have to drive a higher amount of Pixels per second in 2d mode, but with Nvidia the border is higher.

Computerbase has a graph with two and three monitors connected to each card, illustrating my point:
https://www.computerbase.de/2016-07...nahme-des-gesamtsystems-multi-monitor-betrieb
The 1060 runs 30W lower with two screens, but only 15W lower with three screens.

edit:
Polaris seems to prefer single-monitor operation though, where it can be quite efficient even with high refresh rates:
https://www.computerbase.de/2016-07...ngsaufnahme-des-gesamtsystems-windows-desktop