Will 2 non-SLI GPUs split load when running 3 monitors in BS?

[GregP]

Having gotten my 17" touchscreen working over the weekend, I'm now using it in concert with my 37" main monitor and Dick Dastardly's Touch-buddy profile. TB works flawlessly, but I'm taking a huge framerate hit by having to render an effective 3968x1080 resolution (1024 on left touchscreen, 1920 on center, 1024 on right 'phantom' monitor), which drops FPS down to single digits and is basically unplayable.

 

I also have a 22" widescreen that I want to add to this setup, so that in place of the right phantom monitor I'd be adding a 1680 screen, meaning now my effective resolution would be 4624 - ouch. To do this, though, without a Matrox TripleHead2Go device, I obviously need a second video card but I do not want to do SLI - rather, I want to buy a lesser card. What I'm wondering is, will the second card assume some significant portion of the load of rendering this massive 4624x1080 resolution? If I hook the second card up to the 22", and the first (which is more powerful) to the 17" and 37", would this be expected to give me any kind of improved framerate, or would it not make any difference? I'm wondering if maybe BS would consider the first video card the 'main' card and therefore somehow do the entire rendering job via that card instead of split between the two.

[GregP]

So, am I asking a really obvious and dumb question here? Or just nobody knows the answer? :)

 

Maybe what I'm suggesting is not even possible for 3D apps. I know a second vid card can run additional monitors for 2D stuff, but maybe 3D apps use only the main graphics adaptor, and thus the need for something like TH2GO.

 

Well, I'll find out in a few days when my other video card arrives.

[Feuerfalke]

IIRC Urze had his monitors split up on several graphics cards.

 

 

Check out this forum:

 

http://forums.eagle.ru/forumdisplay.php?f=46

 

or this

 

http://forums.eagle.ru/forumdisplay.php?f=39

[GregP]

Thanks for that, Feuerfalke, some useful info there.

 

Basically I answered my own question last night when my second video card arrived in the mail:

 

Under Vista, I actually seem to see a 20-30% framerate DROP by adding a 3rd screen. Without the second video card, using my leftmost 1024 monitor, center 1920 monitor, and no right monitor (but specifying my "width" in options.lua as 3968, what it would have been had the rightmost monitor been there, which is what DCS requires in order to center the screens properly), I seemed to be getting framerates in the 30's.

 

When I added the second video card, and actually output the rightmost screen (blank other than the DCS loading screen and comms menu, when I use it) but kept my options.lua "width" the same, framerate seemed to drop to low 20's.

 

I have no idea why this would be, but for now it seems that it's smarter to just not use the 3rd monitor.

[AlphaInfinity]

Greg,

 

A few questions. Are you running this in windowed mode or full screen? Can you post you config for running two monitors with a single card in Vista?

 

 

Thanks!

[GregP]

I'm running in windowed mode because BS crashes if I try to use more than one monitor in fullscreen mode.

 

My config is as follows - note that my left screen is using Dick Dastardly's awesome touch-buddy profile:

 

options.lua:

 

["graphics"] =

{

["multiMonitorSetup"] = "dd_shkabr+cam+phantom",

["color"] = "32",

["heatBlr"] = 1,

["scenes"] = "high",

["water"] = 2,

["fullScreen"] = false,

["visibRange"] = "High",

["aspect"] = 1.777777,

["textures"] = 2,

["shadows"] = 3,

["display_mode"] =

{

["avi"] =

{

["bpp"] = 32,

["resolution"] = "640x480",

["full_screen"] = false,

["aspect"] = 1.333333333,

["height"] = 480,

["width"] = 640,

}, -- end of ["avi"]

}, -- end of ["display_mode"]

["effects"] = 2,

["haze"] = 1,

["lights"] = 2,

["height"] = 1080,

["resolution"] = "3968x1080",

["civTraffic"] = 0,

["width"] = 3968,

}, -- end of ["graphics"]

 

DD_ShkABR+Cam+Phantom.lua:

 

Description = 'Shkval & ABRIS on the left, camera on the center'

Viewports =

{

Center =

{

x = 1024; --(the width of your leftmost monitor)

y = 0;

width = 1920; --(the width of your primary monitor)

height = 1080; --(the height of your primary monitor)

viewDx = 0;

viewDy = 0;

aspect = screen.aspect;

}

}

 

Shkval =

{

x = 13;

y = 13;

width = 486;

height = 306;

}

 

ABRIS =

{

x = 585;

y = 157;

width = 366;

height = 447;

}

 

This works pretty well under Vista; in Instant Action I get framerates in the mid-30's, down from low 50's with a single screen.

[GregP]

OK, so I went back and did a more rigorous test of what effect adding the second video card had, and the short answer is: it ain't good. :(

 

My testing conditions were: Vista, 1024x768 on left and right monitors, 1920x1080 on center.

 

First I tried all 3 screens (primary video card has center and right screens, secondary has left) and I get a steady framerate of 20 FPS.

 

Then I disconnected the right monitor, removed it from the multiple-monitor config in Nvidia Control Panel, and now I get 40 (!) FPS.

 

I then reconnected the right monitor but this time to the secondary video card and moved the left monitor to primary (just to verify first results): 18 FPS.

 

So - running two video cards and three monitors, non-SLI, non-TH2GO, non-SoftTH, I am seeing a framerate drop of 50% over the single-card, two-monitor configuration - ouch! I guess that means I'll need to remove the third monitor from NVCP each time I want to fly the Shark. Annoying, but at least I get my frames back.

 

Now if I could only get the in-game framerate counter and controls indicator to work - nothing I've done yet has solved this one, including the Phantom Monitor Fix when using two monitors.