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Off-Topic Discussion => General Discussion => Topic started by: Redstreblo on October 20, 2011, 01:42:37 am

Title: Dual Monitors with SLI setup, where to plug in monitors
Post by: Redstreblo on October 20, 2011, 01:42:37 am
I just installed a second GTX 560 Ti in SLI in my PC and I have a dual monitor setup. I want to know if plugging both monitors into the Primary GPU affects performance any. Would plugging one monitor into each GPU improve performance?

Gigabyte X58A-UD3R MB
Intel i7 960 Quad Core CPU
12 GB RAM
EVGA GTX 560 Ti (2 in SLI)

Primary Display - 1920X1080

Secondary Display - 1680X1050
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Klaustrophobia on October 20, 2011, 01:45:28 am
i would imagine nvidia should have this information somewhat readily available on their website.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Redstreblo on October 20, 2011, 01:38:30 pm
Nvidia has nothing about this on their website or FAQ section, this is why I was asking the all knowing internet.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: pecenipicek on October 20, 2011, 01:41:02 pm
as far as i know, doesnt matter in the slightest where you plug it in.  plug em in one or the other.

Also, klaustrophobia is correct, its somewhere on their website.

[edit] a minute of looking around the website reveals this (http://www.slizone.com/object/sli_multi_monitor.html#display)
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Redstreblo on October 20, 2011, 01:59:37 pm
as far as i know, doesnt matter in the slightest where you plug it in.  plug em in one or the other.

Also, klaustrophobia is correct, its somewhere on their website.

[edit] a minute of looking around the website reveals this (http://www.slizone.com/object/sli_multi_monitor.html#display)

Ok, so what it looks like to me is that you have to have your monitors plugged into the same graphics card with a SLI setup. After reading that I don't think that the second card will actually output any signal - strange because I thought with this I could set up 4 monitors if I wanted to (apparently I would need a third GPU for that).
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: LHN91 on October 20, 2011, 02:08:27 pm
^As far as I know and if memory serves, the only cards that support more than two monitors at a time on anything like a matched multi-card setup are Radeons with Eyefinity, which can do three screens per card.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: pecenipicek on October 20, 2011, 03:48:16 pm
as far as i know, doesnt matter in the slightest where you plug it in.  plug em in one or the other.

Also, klaustrophobia is correct, its somewhere on their website.

[edit] a minute of looking around the website reveals this (http://www.slizone.com/object/sli_multi_monitor.html#display)

Ok, so what it looks like to me is that you have to have your monitors plugged into the same graphics card with a SLI setup. After reading that I don't think that the second card will actually output any signal - strange because I thought with this I could set up 4 monitors if I wanted to (apparently I would need a third GPU for that).
forget more than 2 screens with a SLI setup. you can use the 4 outputs just fine if you dont use SLI however.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Astronomiya on October 20, 2011, 08:17:15 pm
Quote from: pecenipicek
forget more than 2 screens with a SLI setup. you can use the 4 outputs just fine if you dont use SLI however.
Not so.  You can use three DVI monitors with SLI in NVSurround.  One of the advantages of Eyefinity over NVSurround is that it doesn't require SLI/Crossfire.  Just plug the first two monitors into the primary card and then use one of the DVI outputs on the secondary.  This is exactly what I did with my GTX 460's before I bought my current Radeon 6970's, and it worked like a charm.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: pecenipicek on October 20, 2011, 08:30:44 pm
Quote from: pecenipicek
forget more than 2 screens with a SLI setup. you can use the 4 outputs just fine if you dont use SLI however.
Not so.  You can use three DVI monitors with SLI in NVSurround.  One of the advantages of Eyefinity over NVSurround is that it doesn't require SLI/Crossfire.  Just plug the first two monitors into the primary card and then use one of the DVI outputs on the secondary.  This is exactly what I did with my GTX 460's before I bought my current Radeon 6970's, and it worked like a charm.
as i have never owned a SLI/Crossfire setup, and i only do a dual-monitor setup, i honestly couldnt say yes or no to this. if it works, great, if it doesnt, oh well.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Redstreblo on October 20, 2011, 11:11:19 pm
I am interested in this because I have seen videos of people playing games with three monitors where the primary monitor is in the center with the crosshair and the other monitors on each side giving a better periferal view of the battlefield or whatever (Like a flight sim where you are looking in all directions at once). I'm wondering if you need some sort of special set up for that.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: LHN91 on October 20, 2011, 11:15:59 pm
Just did a quick bit of research over on Nvidia's site, apparently with NVSurround you can do that but only with an SLI setup and only on windows 7.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Astronomiya on October 21, 2011, 05:05:04 pm
Correct.  With Eyefinity you only need one 5 or 6000 series card and at least one monitor that can take DisplayPort, or an active DP-DVI adpater - these cost about $100 (Win7 is probably required too, but you already have it anyway).  However, Eyefinity has one drawback in that you will unavoidably get screen tearing on at least one monitor due to the mismatched output types.  Unlike NVSurround, in Eyefinity all monitors in a single display group must be connected to one card.  Either multi-monitor solution will work very well, and playing games on three monitors is quite a treat.  I will caution that some games/game engines don't play nice with it (UE3, I'm looking at you), but the rest tend to run beautifully if you have the graphics horsepower to run at ridiculous resolutions.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: pecenipicek on October 21, 2011, 11:15:20 pm
there's also the ever-lovely X11 stuff for linux fanatics... :D
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Redstreblo on October 21, 2011, 11:30:50 pm
....(Win7 is probably required too, but you already have it anyway)....

Who told you I was running Windows 7!?  :nervous:
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Davros on October 22, 2011, 04:06:27 am
Correct.  With Eyefinity you only need one 5 or 6000 series card and at least one monitor that can take DisplayPort, or an active DP-DVI adpater - these cost about $100

not so, more like $25
http://www.google.co.uk/products/catalog?q=sapphire+displayport+to+dvi&hl=en&prmd=imvns&bav=on.2,or.r_gc.r_pw.,cf.osb&biw=1591&bih=823&um=1&ie=UTF-8&tbm=shop&cid=4459337367729226641&sa=X&ei=ToeiTsaqOcjLtAbJ3dXnAg&ved=0CFsQ8wIwAA
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Astronomiya on October 23, 2011, 01:02:38 am
Quote from: Redstreblo
Who told you I was running Windows 7!?  :nervous:
Call it a lucky guess.  Or maybe I'm just psychic.

Davros, I stand corrected on that front.  However, that particular one only does single-link DVI.  The dual-link DVI adapters are still more expensive.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: pecenipicek on October 23, 2011, 06:23:50 am
Quote from: Redstreblo
Who told you I was running Windows 7!?  :nervous:
Call it a lucky guess.  Or maybe I'm just psychic.

Davros, I stand corrected on that front.  However, that particular one only does single-link DVI.  The dual-link DVI adapters are still more expensive.
you dont need better than single link for 1920x1080@60Hz per screen
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Redstreblo on October 23, 2011, 11:37:23 pm
Quote from: Redstreblo
Who told you I was running Windows 7!?  :nervous:
Call it a lucky guess.  Or maybe I'm just psychic.

Davros, I stand corrected on that front.  However, that particular one only does single-link DVI.  The dual-link DVI adapters are still more expensive.
you dont need better than single link for 1920x1080@60Hz per screen

Not if you want to use 120Hz monitors. I wonder about those, the human eye can only perceive about 30 FPS I think and VSinc takes care of screen tearing issues  (How badly does VSinc affect your performance?) so why go the expensive route?
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: KyadCK on October 24, 2011, 02:13:38 am
^As far as I know and if memory serves, the only cards that support more than two monitors at a time on anything like a matched multi-card setup are Radeons with Eyefinity, which can do three screens per card.

Three is aiming a little low, Radeons can put out up to five screens each.

Not if you want to use 120Hz monitors. I wonder about those, the human eye can only perceive about 30 FPS I think and VSinc takes care of screen tearing issues  (How badly does VSinc affect your performance?) so why go the expensive route?

I think its 30fps for TV because of motion blur. Otherwise I hear 60fps is the limit, but people claim to see the difference for 120, so who knows.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: pecenipicek on October 24, 2011, 06:08:14 am
Quote from: Redstreblo
Who told you I was running Windows 7!?  :nervous:
Call it a lucky guess.  Or maybe I'm just psychic.

Davros, I stand corrected on that front.  However, that particular one only does single-link DVI.  The dual-link DVI adapters are still more expensive.
you dont need better than single link for 1920x1080@60Hz per screen

Not if you want to use 120Hz monitors. I wonder about those, the human eye can only perceive about 30 FPS I think and VSinc takes care of screen tearing issues  (How badly does VSinc affect your performance?) so why go the expensive route?
i've bolded the important bit in my post.

in short, if you need better than 60Hz, you're a wanker, end of story.

(refresh rate on CRT's != refresh rate on LCD's, if anybody tries doing that argument...)
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Nuke on October 24, 2011, 09:24:31 am
i think 120hz is a waste on multi-screen configurations. its nice to have as one big screen, and really only so you can have stereo 3d. you get the videophiles claiming they can tell the difference and will buy them for wankery. for multi-screen 3d to work all the monitors would need to be in sync. if they dont all refresh simultaneously the shutter glasses wont work. so all these monitors would need to support it. with the way graphics are progressing 60hz will soon be impossible for games, even john carmack has decided to go 30hz on post rage titles.

and **** multiple monitors i want one of those hemispherical projection screens :D
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Astronomiya on October 24, 2011, 06:59:13 pm
I think its 30fps for TV because of motion blur. Otherwise I hear 60fps is the limit, but people claim to see the difference for 120, so who knows.
It has to do with the fact that GPUs and monitors draw and count frames differently from the way TVs and movie projectors do.  This is why a reported 30 FPS can be choppy in-game, but a 30 FPS TV broadcast appears perfectly smooth.  I notice a difference between 120 Hz and 60 Hz refresh on my roommate's TV as well; the picture is sometimes jarringly smooth (odd wording, I know, but it is what I see), since I'm not used to seeing a TV broadcast be as fluid as the 120 Hz TV can display it.  This happened to me when I saw Captain America in the theater too - it was shown on a new 120 Hz digital projector instead of at the traditional 24 FPS.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: KyadCK on October 24, 2011, 08:18:46 pm
Quote
It has to do with the fact that GPUs and monitors draw and count frames differently from the way TVs and movie projectors do.

TVs and projectors are no different at all from a computer monitor, no idea where that idea came from. The effect movies and TV use is called motion blur. GPUs use motion blur when they play movies too, Its just how the frames are saved and have nothing to do with what is playing them. There is no magical difference between a GPU and the video out on a dvd player, its all about what is being played. S-Video is a nice example of this since DVD players and some older GPUs both have it. Or the fact TVs have VGA and DVI ports.

Motion blur is the concept that the human eye sees changes, or motion, rather then each frame on its own. This is also why you don't get a clear picture when you pause a movie during anything involving movement, and why 24fps seems smooth in a movie and not a game. They do it to save data amount and bandwidth which leads to point number two...

Quote
TV broadcast be as fluid as the 120 Hz TV can display it.

How certain are you that the TV signal is 120hz? I can pretty much guarantee it is not. TV also uses motion blur, and I would be amazed if any company decided to use about four times the bandwidth for little to no gain.

Also, not all TVs are 'true' 120hz TVs, but simply refresh the same frame twice. As far as I know, you would need HDMI, DVI or DisplayPort input from a computer to get 'true' 120hz anyway since again, movies use motion blur and still only play at ~30fps, 60 if 3D.

I will not comment on theater projectors though, cause I've never seen what they use. For some reason I doubt they use the same bluray disk everyone else uses.

Quote
and **** multiple monitors i want one of those hemispherical projection screens

I love my four screens, but hell yes!
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Nuke on October 24, 2011, 08:37:36 pm
some tv formats update only half the lines and then the other half, or interleave (this is what the i means in 1080i). this was actually done to reduce flicker on old skool analog tv, i think we only keep it to reduce the required throughput. a computer monitor scans all lines in one pass. there are tv formats that do this too, so the line between tvs and monitors are really starting to get blurred. my monitor is 1080p for example.
120hz tvs do interpolation to upsample the 30? fps (not really sure if its still 30) signal, where as a 120hz computer monitor accepts a 120hz signal.

dont bother considering the different signal interfaces. all the signal conversions are done in the electronics, likely in the driver ic or other electronics. most modern signal interfaces are simple, speorating out the analog data from the sync signals or just using digital signaling. the signals that are hard to process are the older analog composite signals which attempted to cram all the luminosity, chrominance, and sync data all into one channel for brodcast.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: KyadCK on October 24, 2011, 11:04:47 pm
Alright, there is interleaving, but I was referring more to
Quote
This is why a reported 30 FPS can be choppy in-game, but a 30 FPS TV broadcast appears perfectly smooth.
In which case the only reason 30fps TV is smooth is because of motion blur, not because of some magic that TVs have that monitors wouldn't support. Could have made that more clear I spose.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Davros on October 25, 2011, 12:22:08 am
120hz monitors are for 3d. no one buys them for the increased refresh rate
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Nuke on October 25, 2011, 12:36:01 am
Alright, there is interleaving, but I was referring more to
Quote
This is why a reported 30 FPS can be choppy in-game, but a 30 FPS TV broadcast appears perfectly smooth.
In which case the only reason 30fps TV is smooth is because of motion blur, not because of some magic that TVs have that monitors wouldn't support. Could have made that more clear I spose.

i think youre confusing motion blur for the artifacts caused by interlacing. read this (http://en.wikipedia.org/wiki/Interlaced_video), especially the part on problems caused by interlacing. while some blurring is done to reduce these artifacts it is not motion blur.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: KyadCK on October 25, 2011, 02:10:54 am
Interlacing is as you started above, and in the images available, show distinctive lines (alternating horizontal bars being in different frames). I can say from experience that pausing TV (for comparison sake, satellite, composite video to 1080i crt TV, possibly runs in 480p? I doubt it upscales) does not cut so cleanly, or anything near it, and does in fact look like the middle image here (http://en.wikipedia.org/wiki/Motion_blur#Restoration). If the blurring effect from interlacing artifacts are near that level, then oops, my bad, at least it looks close to the same.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Fury on October 25, 2011, 03:07:20 am
in short, if you need better than 60Hz, you're a wanker, end of story.

you get the videophiles claiming they can tell the difference and will buy them for wankery.

120hz monitors are for 3d. no one buys them for the increased refresh rate

Sad statements are sad. If you compare a true 120Hz LCD monitor to equivalent 60Hz LCD monitor, there is a clear difference how smoothly fast moving scenes are displayed. This can be visible even in normal Windows desktop if you pay attention to how quickly ghosting disappears (or lack thereof) when moving windows around fast. If one wants the best LCD monitor for gaming, one should get one of those true 120Hz LCD's because they simply are better at the job than 60Hz LCD's. And this is disregarding 3D.

If you can't see the difference, good for you. But if you want to call others wankers because they can, you're a wanker yourself.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Nuke on October 25, 2011, 04:44:10 am
oh im sure theres a difference. provided you can find a 120 hz video source. i especially like how the monitor refresh is going up, while the trend in gaming is heading towards a 30hz refresh rate, to allow for higher quality content and still have it be possible to render in real time. there may even be a market for high framerate video and possibly tv, provided the tech is up to snuff. 120hz dependent 3d is also a bad idea for anything other than movies. especially when there are more viable alternatives, like affordable hmds and autostereoscopic displays that can update visual fields simultaneously and render at lower framerates without causing headaches from flicker.  the technology is too new, so i reserve my opinions until the technology proves itself. id hate to have a 120 hz screen that is displaying 30 or 60 hz content interpolated to use the higher refresh. so getting it now, is most definitely wankery.

Interlacing is as you started above, and in the images available, show distinctive lines (alternating horizontal bars being in different frames). I can say from experience that pausing TV (for comparison sake, satellite, composite video to 1080i crt TV, possibly runs in 480p? I doubt it upscales) does not cut so cleanly, or anything near it, and does in fact look like the middle image here (http://en.wikipedia.org/wiki/Motion_blur#Restoration). If the blurring effect from interlacing artifacts are near that level, then oops, my bad, at least it looks close to the same.

any motion blur in the content is merely an artifact from the recording technology, not a feature or defect in the display technology. a frame will contain all the data that was picked up by the film/ccd while it was being exposed/sampled. the longer the exposure, the more the motion blur will be manifested and a shorter exposure will produce very sharp frames. when dealing with an interlaced format it was preferable for sharpness to be avoided so that interlacing artifacts would be less visible. this is not really an issue with progressive scan formats (which are better suited to crisper video). needless to say interlacing is archaic and id like to see it die. only reason we still use it for 1080i is to reduce the bandwidth requirements so it can be broadcasted on the available channel.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Davros on October 25, 2011, 05:52:07 am
If you can't see the difference, good for you. But if you want to call others wankers because they can, you're a wanker yourself.

Woah, where did I say there is no difference ?
all I said is the reason people by 120hz monitors because they can display 3d, not because of image quality (notice I made no mention of what panel has superior iq)

no doubt you bought a 120hz panel because you care about iq (although thats not the reason most people buy them) and i'm glad that you can view images in better quality than most on your 6bit panel.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Fury on October 25, 2011, 08:07:18 am
120Hz panels do not have better image quality than 60Hz, image quality depends solely on panel type (and quality) in use regardless of refresh rate. Also, I do not own a 120Hz LCD display.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Davros on October 25, 2011, 08:44:51 am
@fury i was being sarcastic ;)
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Astronomiya on October 25, 2011, 07:14:30 pm
TVs and projectors are no different at all from a computer monitor, no idea where that idea came from. The effect movies and TV use is called motion blur. GPUs use motion blur when they play movies too, Its just how the frames are saved and have nothing to do with what is playing them. There is no magical difference between a GPU and the video out on a dvd player, its all about what is being played. S-Video is a nice example of this since DVD players and some older GPUs both have it. Or the fact TVs have VGA and DVI ports.

Motion blur is the concept that the human eye sees changes, or motion, rather then each frame on its own. This is also why you don't get a clear picture when you pause a movie during anything involving movement, and why 24fps seems smooth in a movie and not a game.
Films don't add motion blur after the fact; the individual frames are blurry during rapid movement because of the non-zero shutter speed of the camera, as Nuke mentioned.  A game has effectively zero shutter speed, hence the jerkiness.  In that way, you're right, I said the wrong thing.  I should have said that camera-based sources and purely GPU-driven sources like games are created differently in general, and those differences show up when they're displayed.

Nuke got most of the rest, but I'll note that if the signal is not an integer divisor/multiple of the refresh rate, you'll get periods where the picture is very smooth and periods where it appears a little jerky.  The current NTSC standard is almost-but-not-quite 30 FPS (it's 29.97), so you will see some periods of jerkiness on a 120 Hz TV viewing a US signal, and some smoother than normal segments.

Quote
How certain are you that the TV signal is 120hz? I can pretty much guarantee it is not. TV also uses motion blur, and I would be amazed if any company decided to use about four times the bandwidth for little to no gain.

Also, not all TVs are 'true' 120hz TVs, but simply refresh the same frame twice. As far as I know, you would need HDMI, DVI or DisplayPort input from a computer to get 'true' 120hz anyway since again, movies use motion blur and still only play at ~30fps, 60 if 3D.

I will not comment on theater projectors though, cause I've never seen what they use. For some reason I doubt they use the same bluray disk everyone else uses.
As Nuke mentioned before I could, the TV signal isn't 120 Hz, the TV interpolates frames.  Since TV signals are filmed using 1/30 second shutter speeds (in the US), they will be blurred just like films are.  So yes, TV being smooth is partially due to motion blur, but I wouldn't call it an effect that it uses.  Film theater projectors use the same 24 FPS film stock they always have (this is why DVDs and BDs play at 24 FPS in the first place).  A 120 Hz digital projector then performs a similar interpolation procedure to the TV.  The digital projectors also don't use a BD, obviously, but basically do use a much higher-resolution version of it (4K* as opposed to 1080p).  The raw audio quality is the same these days thanks to the BDs inclusion of lossless audio codecs, but obviously the speaker systems usually aren't even in the same league.

*4K res = 4096x2160.  Some projectors for smaller screens use 2K = 2048x1080 instead, so just barely better than BD!
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Nuke on October 25, 2011, 11:08:33 pm
i should point out that we dont use ntsc anymore (at least for not broadcasting, most consumer a/v hardware still have support for ntsc formats), those standards have been replaced by atsc (http://en.wikipedia.org/wiki/ATSC). these support 60 hz progressive scan on all modes but 1080i, however new compression standards allow 1080p 60fps. of course the actual framerate depends on the broadcaster or satellite/cable provider (atsc supports a ridiculously wide range of formats). best case scenario you still need to interpolate an entire frame. so im not buying a 120hz tv any time soon.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: KyadCK on October 25, 2011, 11:20:34 pm
Fair enough, I worded it poorly too. Can we settle on an effect it has?

A 120Hz TV is still completely incapable of showing more DVD data then a 60Hz TV because the data it self doesn't change. Same is applied to VHS, Blu-Ray, or any other pre-recorded media designed for 60Hz interlaced. Following this, the only method to make it 120Hz would be to flash the same frame twice. While this may reduce any flicker your eyes can pick up, the picture is not better, no more is shown. Again, the theater may have special media, but if it is 3D, then you're still at 30fps and thus no smoother (120Hz interlaced assumed).

@Nuke: I think it would also be fair to say that the FPS is also dependent on the recorded media if the show is not live, and the camera used if it is.
Title: Re: Dual Monitors with SLI setup, where to plug in monitors
Post by: Nuke on October 25, 2011, 11:51:55 pm
@Nuke: I think it would also be fair to say that the FPS is also dependent on the recorded media if the show is not live, and the camera used if it is.

that matters too in selecting a format. you dont want to use a 60hz format on a 30hz source when you can trade it for resolution. you can also trade off resolution for refresh as needed. some broadcasts, like sports, benefit from a non-interlaced format, as they like to have a sharp picture using a fast shutter speed, this allows the ball or whatever to be more visible on the screen. movies at 24fps up-sample well to 60hz interlaced. regardless the point im trying to make is that there is no 120hz content at the moment.