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Forums -> Multiple monitors -> Multimonitor 3D gaming & PCIe
Douglas Houston   2005-05-13 12:53
I am really interested in setting up a 3-monitor system for use in flight simulation, e.g. Microsoft Flight Simulator 2004. I have seen this game running in a 3-monitor setup (3 projectors to be exact) using the Parhelia card, and it's amazing. I'm hoping with the advent of PCI Express multi-graphics card systems will mean that you can have multiple cockpit views as well as a high framerate. Does anyone know if it will be possible to use e.g. two PCIe NVidia cards to power 3 (or even 4) monitors in 3D? Does the game in question (e.g. FS 2004, Pacific Fighters, Lock On 1.1) have to specifically support such a mode?
Douglas Houston   2005-06-06 12:06
So I guess no-one can tell me anything about PCIe multimonitor gaming ..?
jet   2005-06-06 14:32
Matrox has released a Matrox Parhelia PCI express X16 card that will do the 3 monitor games for you. I have been using one now since April for all my games since I built my new system from my old Parhelia AGP X8 that I had been using for two years. Look on Matrox's site to see all the 3 monitor games they support Hope this helps.

jet
Slaughterer   2005-06-07 10:59
I have no SLI experience, but I've got two (AGP/PCI) cards and I'm trying to do the same as you - triple-monitor gaming. Here's what I've learned.

I think the situation is this: apps can commonly handle multiple monitors being driven from a single card, but they have trouble with multiple cards. This is why Matrox has it so easy with their triplehead boards.

I wish Nvidia, with their unified drivers, would address this by allowing all of the boards to "appear" to the OS as a single card driving three or four monitors. IE to span across multiple graphics cards. But it currently doesn't work that way.

I have an AGP 6800 and a PCI 5200 and I can't get anything to run across all three cards. I've learned (from Christian Studer) that OpenGL has trouble with multiple graphics cards, while DirectX has built-in support for such things. So your success rate may depend on which API your game is written for. I'm trying to play id games, so I'm SOL so far. I tried FS2004 and I could use the three monitors, but I couldn't span a single view across multiple graphics boards. I'd like to have one big wide cockpit view, but I couldn't make it happen.

Best of luck, and please share any success you have with us.
Gen_firestorm   2005-06-07 20:20
what the... sli... can only work with direct draw drivers. cd hardware uses ALOT... of memory not to mention intturupts. 3 cards to run would requre a game to sync to 3 hardware devices and run 3 seperate 3d engines in sync... its not possible. only voodoo knew how to do that.
Douglas Houston   2005-06-07 23:35
I found something interesting here:

"Multimonitor configurations of PCIe are expected to work just like PCI. Whether they do will depend on the motherboard manufacturers. For example, x16, x8, and x8 triple monitor configuration will necessitate the existence of one x16 and two x8 slots on the motherboard."

Not sure if it's relevant to gaming; has anyone got any kind of game to work on any kind of system that does not have the Parhelia card? If not then I guess the PCIe idea won't work.

I've seen the Parhelia card in action, the only trouble is that it's a bit underpowered for games like Lock On: Modern Air Combat etc. I was hoping there would be some way to use less specialised (and less expensive) cards from ATI or nVidia.

Gen_firestorm wrote:
"3 cards to run would requre a game to sync to 3 hardware devices and run 3 seperate 3d engines in sync... its not possible. only voodoo knew how to do that. "

Not sure what you mean ... wouldn't two cards running in SLI mode be treated as one card? (On the other hand, if they were in SLI mode would the video outputs of the second card still be enabled?). There definitely wouldn't be 3 cards - even the fanciest motherboards I've found can only take 2 PCIe video cards. I guess you'd have one card powering the centre monitor (and perhaps another monitor showing control panels) and the other card powering the left and right views.
jbigger   2005-06-08 09:38
I have run several games across all three monitors. I'm still using a 8X AGP TI4200 and a PCI fx5200. I posted a quick site detailing
the process but I had some trouble with the original so here is a link to the same page (different address)

3 mon gaming:
http://bigger1.home.mchsi.com/about.htm

the "my system" link is broken but my system in the gallery is 6100 (if I remember correctly)

hope it helps somebody
JB
Douglas Houston   2005-06-08 10:11
Wow, I had a look at your website and that looks pretty cool. One thing I noticed from the screenshots was that the information displays in the games (e.g. the compass in Call of Duty) were ovals rather than circles - does this mean that widening the resolution just stretches the normal view, rather than actually widening your field of vision?

You mentioned that FS2004 you could select views to display on different screens so is this game the exception? Do you (or anyone else) know of any other flight sims that can do this?
Douglas Houston   2005-06-08 13:51
OK, so I found here that it looks as if you definitely can't use the cards in SLI mode to power more than one display, but that doesn't mean you couldn't have them running as separate cards ...

"SLI only works on one display, at least for right now. This means anyone using two monitors or TFT displays has to deactivate the SLI mode for normal work in Windows and reactivate it when needed, which always requires a restart."
Slaughterer   2005-06-08 15:15
Jeff, I'm about to try to use some of your tips for Quake3 and Doom3. Great to see somebody knows how to do this. Thanks!
Slaughterer   2005-06-08 15:24
I think it's time to post an exchange I had with Christian Studer, of RealTimeSoft. It's long. Read from top to bottom.

--------------------------------------------------

Christian,

I can't find any good information on any of the message boards out there. I get conflicting information from people who don't really know. After looking around this site, it's clear that you're someone who would know. I get hardly any responses at all on the Nvidia forums. I hope you'll answer a couple questions about multi-monitor gaming and screensavers. If you're pressed for time, please skip to the red paragraph at the bottom. I thank you for your time.

I have three identical flat panels -- two connected to an Nvidia 6800 AGP (from BFGTech) and one connected to an Nvidia 5200 PCI (the newest PCI Nvidia board I could find, from eVGA). I'm running the 71.89 drivers direct from Nvidia. I'm using the dualview modes and not spanning. There is no option to span all three monitors. My PC is well endowed (P4 2.8GHz, 1GB RAM) and my Windows XP Pro is up-to-date with the latest Microsoft updates. Everything works splendidly for everyday work.

I'm stymied by screensavers that work only on one monitor (the primary) or only on two (the two connected to the 6800 card). I've found that any screensaver from Microsoft works across all three just fine. I'm currently using the Moiré screensaver that they provided as an example in one of their SDKs. I've found many other screensavers that claim to do what I want but they don't. Some crash to a BSOD if asked to draw on all three. Some beautiful screensavers that I'd love to use are Cosmic Voyage, Euphoria, Flurry, Matrix Reality 3D, and so on.

I'm also stymied by Quake 3. I'd love to run it across three monitors. FPS games don't work with just two because the crosshair is in the center, but on three it should be great. The farthest I've been able to get is to run it in a 3840x1024 window, and position the window properly. But the game only draws to the monitors attached to the 6800, because my primary display is on the 6800. If I set the monitor on the 5200 to primary, the situation reverses. Performance in every case is stellar, high enough to make me think the system can handle this request if it's technically doable.

Can OpenGL draw across two display cards? Can DirectX? Do Microsoft's screensavers use DirectX instead of OpenGL? Is that why they work? Do other screensavers fail due to sloppy programming? Is there some software product that can help me? It looks like UltraMon does a lot of neat things but I don't see that it can help me with these issues. Has Nvidia ever supported spanning across graphics cards without SLI?

Thank you very much. Any assistance you can provide is greatly appreciated.

Sincerely,
Slaughterer

--------------------------------------------------

Hi Todd,

the problem is that most applications haven't been designed for multiple monitors, and OpenGL drivers don't always support multiple monitors. UltraMon won't help with this, and I'm not aware of any application which would.

For OpenGL, the multi-monitor support needs to be provided by the OpenGL driver. Nvidia used to support hardware-accelerated OpenGL across multiple cards, but this doesn't seem to work with newer drivers, even though the option is still available (Nvidia tab > OpenGL Settings > Multi-display hardware acceleration).

That's why Quake3 only draws on the monitors connected to the primary video card.

Direct3D has native multi-monitor support. The Moire screen saver is a good example, it creates a distinct 3D device for each monitor, meaning the graphics for each monitor are drawn fully accelerated by the video card driving the monitor.

Direct3D also supports stretching a 3D window across multiple monitors (and video cards), the application doesn't need to do anything special to support this. But performance will suffer, because the rendering is actually done by only one card, and the result gets blitted to the window.

I'm not aware of any video card manufacturer which offers span mode across multiple cards. Some Nvidia Quadro cards seem to support accelerated OpenGL across multiple cards (http://www.nvidia.com/page/qfx_600pci.html), but as far as I know SLI is only used to draw on a single monitor with two cards.

Regards,

Christian Studer
http://www.realtimesoft.com
Slaughterer   2005-06-08 15:28
Like the Direct3D blitting solution that Christian mentioned, it ought to be possible for Nvidia to write it into the drivers so that a pair of SLI boards can render to one giant framebuffer and then blit to the display buffers for multiple monitors. This would be IDEAL for multimonitor gaming. If Nvidia allows 3 or 4 monitors to SPAN in the driver, then it's transparent to the software and this would work for OpenGL as well.

Is there anybody from Nvidia here?
Slaughterer   2005-06-08 15:57
JB says on his website:

"I use the video drivers that came in the box with my NVidia fx 5200 card. when I tried to upgrade them 3 monitor gaming wouldn't work. My opinion is this could be most people's problem (But I'm no expert)."



I think you've hit the nail on the head, JB. I had tried Matrox's instructions already, and when I edited my config file to match your instructions, there was nothing to do. But you've confirmed for me that it's an Nvidia driver issue and that it USED to work. That gives me hope. I will now turn to the Nvidia forums to post a formal gripe - er - feature request. ;-)

Thanks again! BTW, do you guys HATE it when I post four messages in a row? I hope that's not "rude" in forum netiquette.
jbigger   2005-06-10 10:41
To answer The question by Douglas Houston on the display view being either widened or streached..
Well, if I understand it correcty..
Although the game menu bars and status displays streach accross the display, the accual "FIELD OF VIEW" in the game is increased when you add or alter "seta r_fov 138". I believe it stands for 138 degrees field of view. I dont recall people or objects in the game seeming real wide.

Any way, I dug out my copy of FS2004 and am installing it now. I'll put pixs on the site if I get any results..

later
JB
Slaughterer   2005-06-10 18:35
I can add to the FOV question. The 3D rendered view will look fine if you widen the FOV, like JB said. The "ovals" you mentioned are 2D overlays, and they are stretched, but it's a small price to pay for multimonitor goodness!
jbigger   2005-06-11 01:24
I added the FS2004 pix to the site and fixed the broken link. Enjoy...

JB
Doug (Douglas Houston)   2005-06-11 02:30
I just read an article HERE that (at least one of) the new 7-series cards from Nvidia will have two DVI outputs. The article doesn't mention if that's in addition to the usual VGA connector, but if it is then the use of multiple videocards for multimonitor gaming needn't be an issue!

Jbigger, can you set FS2004 so that the centre screen has the usual forward-looking view, the left screen has a view out of the left side of the cockpit and the right screen has a view out of the right side of the cockpit?

Do you know of any combat flight sims that can do this (with or without modifying config files, either is fine)?
Doug   2005-06-11 03:27
Actually, I think I jumped the gun there. Seems unlikely that there will be a VGA connector in addition to the 2 DVI connectors as the latest ATI cards only have 2 DVIs:

http://www.bjorn3d.com/read.php?cID=776&pageID=1426
jbigger   2005-06-11 03:29
You mean like this. (see website)
Doug   2005-06-11 04:23
Thanks jbigger.

Man, that is so sweet. I'm going to try it (need to buy another graphics card first!)

What were your framerates like, by the way? Do they drop much when you go multimonitor?
Doug   2005-06-11 04:28
FS2004 should still be able to do this with widescreen (e.g. WXGA) monitors? i.e. you'd get an even wider field of view?
jbigger   2005-06-11 05:02
Well, I played a few minutes and considering the 3 monitors it played pretty well. Normally I have to turn the graphics way down in order to curb slowdown but this game was one of the best at keeping up.

Good luck with it.

JB
Doug   2005-06-14 02:59
Does anyone know if using WXGA (widescreen) monitors will prove a problem with multimonitor gaming? Or can you just specify the custom resolution in the configuration file?

Does FS2004 have e.g. 1280x768 as a resolution option?
John   2005-06-15 19:11
I got it working!

currently, I have 2 video cards, both FX5700LE; one AGP, one PCI. The AGP card is using dualview, and the pci card is only driving one monitor.

I'm using nVidia 71.89 drivers. I haven't played with it much, but I did get Jedi Academy to display across 3 monitors! Yay!
Greg   2005-06-16 02:29
Using GeForce Fx 5600 256MB AGP and GeForce 4 PCI am able to run msfs with no problems accross 4 computer monitors.
Right now I have it set up running 2 monitors and my 51" HDTV using a DVI-HDMI cable and the resolution is good. The S-video sucks. You just need to play a bit. The 5600 recognizes that the HDTV is a HDTV because of the communication accross the HDMI/DVI cable. HDMI supports audio, DVI does not.
gahrens1979@yahoo.com
Uncle-Bob   2005-09-23 03:51
Hi Todd and Christian !

Do you have any news about a way to play open gl or direct 3d gamers acrosse 2 cards without performance loss ?

Did you find any specific drivers ou directx mod ?
Uncle-Bob   2005-09-23 05:31
I just tested the 80.26 forceware (available on guru3D) and I noticed a big performance improvment playing on 3 monitors with 2 6800 Ultra PCIe in opengl.

Doom 3 @ 60 FPS in 2400x600 and Serious Sam 2 @ 45 FPS in 1940x480 (full details...)

Those drivers are great ! You should try them. Thanks Nvidia.
Deam   2006-01-11 04:50
Does this mean the new forceware drivers (80.00+) have no re-implimented openGL on secondary cards?

For the longest time, I could not get openGL to work on the second card. Be it a full screen app, or even windowed openGL.
Deam   2006-01-22 06:01
Anyone?
Forums -> Multiple monitors -> Multimonitor 3D gaming & PCIe

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