Energy efficient Eyefinity setup

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erkan
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Energy efficient Eyefinity setup

Post by erkan » Sat Aug 20, 2011 2:58 pm

Hi guys,

Intro:
Time to upgrade monitor, been running this 23" 1920x1200 monitor for 6 years now (75 watt normal, eco mode=50watt). Cost $1600 and it has THE most annoying 40mm fan inside it (to bad it was not mentioned in the webshop, f"n Dustin Swedish retailer), cant wait to replace it with silent monitor :D

Since 30" monitor consume between 100-200 watt I have been thinking of going for a couple of 1080 monitors instead, the lowest watt 21.5/22" 1920x1080 screens I found consume 23 watt, six of those is off course 6 x 23 = 138 watt. Would like to have 6 screens under 100 watt.

Questions:
-So I guess any Radeon with 6 display ports (HDMI/DVI/etc..) will work with 6 displays?
-Most important, will the GFX board consume more watt at idle if there is six displays connected to it at once? I think I read a review of a GFX board where a dual monitor setup used considerably more watt than just a single display.
-Any 1920x1080 displays under 20 watt?!

Thanks!

faustus
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Re: Energy efficient Eyefinity setup

Post by faustus » Sun Aug 21, 2011 2:11 am

-So I guess any Radeon with 6 display ports (HDMI/DVI/etc..) will work with 6 displays?
I think so, with two caveats:
* There can be at most two monitors on the DVI/VGA/HDMI outputs, the rest must use DisplayPort.
* You need Windows 7 (or possibly Vista); Eyefinity support for Linux and Win XP is poor to non-existent.
-Most important, will the GFX board consume more watt at idle if there is six displays connected to it at once? I think I read a review of a GFX board where a dual monitor setup used considerably more watt than just a single display.
Yes, it will. I have a 3-monitor setup, and the idle power is ~35W higher when using more than one monitor. (The difference is between one and more-than-one, there is no difference between two and three monitors. More detail around the middle of this thread.)
The issue is apparently that the graphics cannot enter the lower-power 2D mode with more than one monitor attached, so it's always running in 3D mode.
-Any 1920x1080 displays under 20 watt?!
None that I know of.

dhanson865
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Re: Energy efficient Eyefinity setup

Post by dhanson865 » Sun Aug 21, 2011 6:09 am

WSGF is a good place to discuss Eyefinity. Lots of people there running 3 or 6 monitors who could answer questions in more detail.

http://widescreengamingforum.com/articl ... finity-faq

and

http://widescreengamingforum.com/forums ... iscussions\

would be a good start.


As to 20W 1920x1080 monitors you can get Dell Professional P2210H 22" that uses 22W per screen but I think you are better off looking for a good screen that has low idle power and focusing less on the max power draw.

For example Asus VE258Q power on mode is <55W but the power saving mode is <0.5W. If all you do is read text all day the 20W LCDs will be fine but for games(motion), movies (motion), picture editing (color) you'll have to put up with a slightly higher power draw or you'll have ghosting and/or poor color reproduction.

erkan
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Re: Energy efficient Eyefinity setup

Post by erkan » Sun Aug 21, 2011 12:05 pm

Wow, 35w seems a bit steep, maybe thats peanuts on the total power bill.

6 x 22 w = 132 w
Say a typical system is around 65w, add 35w for GFX board that is 65+35+132 = 232 w, not that bad when you know six screens are running I have to admit.

Ghosting etc... I dont know, this 7 year old 23" monitor is horrible in that regard, the previous 15" I had was even more terrible, but I did not notice ghosting etc in games, it is worse if you have a black background and move white windows, you can see the trails, so ghosting and refresh is horrible but IMHO that is an overrated factor.

Off topic, I could also tell silent PC is overrated (maybe not) :D , I have lived with this TFT for 7 years and it has the most irritating fan in it, 40 mm fan running at max all the time, you could not ask for worse, but has it prevented me from doing work etc. . not at all, it was disturbing first day I got the screen now I am used to it, only disturbing in the night. Computer is 100% silent.

CA_Steve
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Re: Energy efficient Eyefinity setup

Post by CA_Steve » Sun Aug 21, 2011 12:15 pm

I have two Dell G2410 monitors that I picked up in 2009. They use ~17W ea calibrated. No longer sold by Dell...but I'd hope there are similar monitors out there. CNET always shows power use in their reviews and is a good source of info.

Power behavior of video cards with multiple monitors:
- ATI cards' MemClock stays at 3D speeds. Depending on the card, this means +15-30W.
- NVidia: I've heard both the GPU and Memory clocks don't go to 2D idle speeds...but don't have direct knowledge.

dhanson865
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Re: Energy efficient Eyefinity setup

Post by dhanson865 » Sun Aug 21, 2011 6:10 pm

erkan wrote:Wow, 35w seems a bit steep, maybe thats peanuts on the total power bill.

6 x 22 w = 132 w
Say a typical system is around 65w, add 35w for GFX board that is 65+35+132 = 232 w, not that bad when you know six screens are running I have to admit.

Ghosting etc... I don't know, this 7 year old 23" monitor is horrible in that regard, the previous 15" I had was even more terrible, but I did not notice ghosting etc in games, it is worse if you have a black background and move white windows, you can see the trails, so ghosting and refresh is horrible but IMHO that is an overrated factor.
Well if you are seriously considering buying 6 monitors of any size you could narrow it down to a top two or three to try then buy one of each before buying 5 more and sell/return the one(s) you don't like. It'd be way cheaper than getting 6 monitors you don't like and having to sell/return 6 at a time.

Just a quick data dive on newegg for common monitors with your desired resolution shows:

ASUS VH242H 23.6" 55W 1600 reviews
ASUS VW246H 24" 60W 1300 reviews

now lets look for ones with LED back light and displayPort as well.

ASUS VE258Q 25" 55W 60 reviews
Asus VK278Q 27" 45W 75 reviews
ASUS VE248Q 24" 35W 1 review
ASUS PA238Q 23" 33W 0 reviews
NEC EA232WMi 23" 37W 10 reviews
BenQ BL2400PU 24" 42W 0 reviews
HP LA2306x 23" 42W 0 reviews

That list makes it easy to grab the 24" at 35W or 23" at 33W as a big savings vs the 25" at 55W. Given the panel differences I'd take the VE over the PA but then I'm no expert, I'm just taking a quick stab at this from a scan of specs.

http://www.amazon.com/Dell-Professional ... B002JNM3Q0 has 3 reviews for that Dell monitor so you can see the good and the bad of it. The most negative review is someone using it with a DVI-D connection mentioning poor color and vertical viewing angle. If you can put up with that x6 it's a very good deal in terms of energy usage. If that scares you off you should get a monitor in front of you and consider your options for return/exchange/refund etc when purchasing any monitor you are thinking of getting 6 of.

Of course all of that is based on 1920x1080 as being the only resolution I checked. Open up the options for other resolutions and there may be better choices.

multiplexer
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Re: Energy efficient Eyefinity setup

Post by multiplexer » Mon Aug 29, 2011 1:04 pm

That power consumption that people list above is the maximum power consumption for these monitors, usually at too high brightness levels. I have compiled a long list with actual measured power consumption at a reasonable light level (120-140cd/m2). If you stick to the newest generation LED-backlit TN matrix HD monitors at 24", you will be able to hit between 10 and 15W power consumption per monitor at this brightness level. The best monitors in their class can even go below 10W at this brightness setting, and achieve about 300cd/m2 at 23W (for instance Philips 246EL2SBH, Samsung BX2440 LED). That is way too bright for comfortable viewing, but it shows the efficiency.

I haven't included the type of connection in my list, so I won't go too far in advising for or against specific model numbers, but in general you should be able to easily meet <100W with 6 monitors, even including the extra power your video card consumes.

dhanson865
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Re: Energy efficient Eyefinity setup

Post by dhanson865 » Mon Aug 29, 2011 7:31 pm

It'd be interesting to see a list with power draw at specified brightness levels.

My 42" LCD TV in the living room doesn't vary by more than a few watts no matter how low or high I set the brightness and it is well over 100W for the single screen.

I'll have to try that experiment with the 22" LCD I'm using on the PC. OK we have as measured while typing this message

0% Brightness 23W
33% Brightness 29W-30W
42% Brightness 31W-32W
50% Brightness 33-34W
100% Brightness 39-41W

And the specs say it's 44W Max. (AL2223W) I'm assuming since this screen is rated for 300 cd/m2 you'd run this around 42% Brightness?

FWIW I've been running this monitor at 50% Brightness before now. I might consider dropping the brightness a bit to save power but I'd have to be in a room with no lights and no windows to consider running at 0% brightness. It's pitch black outside and my lighting in this room is 18W of compact fluorescent in a frosted glass fixture on the ceiling (two 9W bulbs and the frosting is so opaque that I can barely tell that it's two bulbs).

multiplexer
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Re: Energy efficient Eyefinity setup

Post by multiplexer » Wed Aug 31, 2011 12:00 am

I'll publish an article about it and some more theory related to monitor power consumption somewhere in September. I'm really busy right now and the 'data' mostly consists of Prad.de and other websites' measurement data. There are some significant differences between different websites and I strive to explain those differences instead of just saying 'well, site A says monitor X uses 20W, while site B says it uses 30W, so we will split the difference and call it 25W' or something. That's why I won't be posting the raw data yet.

Also, LCD power consumption is a minefield in and of itself.

As for your comment on running your monitor at 42% instead of 100 assuming 300cd/m2 brightness rating, that's not entirely accurate. Not because your math is off - it's perfectly fine. But manufacturers seem to limit the low end of the brightness scale, probably for electrical reasons (running the flyback converter for the CCFL backlight in a favourable regimen). Your monitor probably bottoms out at somewhere near 80-100cd/m2 at 0% brightness setting, so I would expect 120-140cd/m2 to be at like 25% brightness. Also, brightness tracking is rarely linear.

As an aside, I can see why CCFL backlights can't be run at very low brightness levels, but what I don't understand is why LED backlights are being set up the same way nowadays. There's no technical reason that I can think of why you should limit LED backlights on the low end, well, maybe advertised contrast. But there are good reasons to want to set your LCD to very low brightness levels, for instance for night viewing (like the use case of plasma screens). Coincidentally, that would make the brightness scale a lot more logical, with 0% brightness actually meaning you can't see a thing. The first and only 'screen' that I've seen that does this is the Lenovo X120e's otherwise mediocre screen. It's great, because it's a netbook that is liable to be used in bed at night, and this way I don't need a night light to comfortably view the screen.

kiblams
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Re: Energy efficient Eyefinity setup

Post by kiblams » Thu Oct 20, 2011 5:51 am

Interestingly I have recently posted an article of my own investigation into the steps you can take for more energy efficient monitors.

Sorry for the self plug, but I have been on the forum for a while and this stuff has become a little hobby of mine, so I gain nothing from you guys reading my work other than a nice warm feeling :D .

Hope it helps.

fastturtle
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Re: Energy efficient Eyefinity setup

Post by fastturtle » Thu Jun 13, 2013 9:28 pm

I've got a nice Dell 2240S that pretty low power. It's also an IPS display - max rating is 35w - that's at 100 percent back lighting.

Got it after New Year from Newegg but Dell still caries them. Decent price to boot for an IPS panel

Don't know about eyefinity as I run Linux and support for more then 2 monitors stinks unless you're using Firegl cards in the $1k range (CAD/CAM) Workstations.

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