# Options for my 3rd screen on 2nd Nvidia card

## Manu311

Hey,

I'm not sure where I should post this, but I think this is the best section for it.

I've got 3 vga monitors and 2 nvidia graphic cards (a good and a not that good one). So both cards only got 2 vga/dvi outs. I've been using the better card with my two 19" monitors and twinview (from nvidias driver).

Now it's impossible to get twinview on those two or even all three monitors, if the third monitor is enabled as well.

If I use twinview and an additional x server for the 3rd monitor - the twinview is no longer able to seperate the monitors, so everyprogram thinks I got a 2560x1024 monitor and maximizes on both (which is definitly not what I want). The only way I evaded that behavior was with 3 x servers and xinerama. Problem then is only a single monitor is able to display opengl and the framerate drops to way below 1% of the usual. So that's not usable neither.

Actually that third monitor is not essential I can live without it - but I would like to display either an mplayer output (please not caca or aa  :Smile: ) or some console. It would also be fine if I could (however) write programs to draw there directly (draw or write, whatever).

Sadly I have not found anything that either solves the issues inside of x (at least not in openbox and the nvidia driver - I like to keep both).

Any programs, tools or advice that could help me?

Thanks in advance.

----------

## Mad Merlin

If new hardware isn't out of the question, the integrated GPU with Ivy Bridge apparently supports 3 monitors (and it works in Linux). Similarly, some newish nvidia cards support 3 displays, I'm not sure how the Linux support is on that though.

----------

## Gusar

As Mad Merlin says, you'll probably need new hardware. Radeon Eyefinity (supported on HD5xxx and up) has 4-6 outputs depending on card, Intel Ivy Bridge has 3 outputs, and Nvidia Kepler (the 6xx series) has 4 outputs with twinview <- yeah, the name now doesn't fit anymore  :Smile: .

The only Kepler card right now is the high-end (read: very expensive  :Smile: ) GTX680, but there should be mid- and low-end Kepler cards coming in the next months. If I were you, I'd wait for those and use only two displays until then.

----------

## s4e8

Ivy bridge 3 monitor setup require 2 DP output with limited resolution, No motherboard equip 2 DP through.

----------

## Gusar

 *s4e8 wrote:*   

> Ivy bridge 3 monitor setup require 2 DP output with limited resolution, No motherboard equip 2 DP through.

 

Where did you read that? Got a link?

----------

## disi

Looks like Xinerama, if you want these combined:

http://nouveau.freedesktop.org/wiki/MultiMonitorDesktop

However, did you try the reverse engineered open source driver for nvidia cards? It has xrandr support for multiply monitors and you don't have to use TwinView.

----------

## Gusar

 *disi wrote:*   

> Looks like Xinerama, if you want these combined:
> 
> http://nouveau.freedesktop.org/wiki/MultiMonitorDesktop

 

It's not just Xinerama, it's Xinerama with a ZaphodHeads trick. Which is a very, very nice trick, I must say, I didn't know it exists. However, if I quote from that page the drawbacks of Xinerama with nouveau... *Quote:*   

> The rendering speed in a Xinerama configuration is practically always worse than what the slowest card is able to achieve alone. Furthermore, Xinerama does not handle GLX, so 3D acceleration is disabled.

 

... that's far from ideal. Nvidia does support 3D with Xinerama, but the rendering speed drawback remains.

 *disi wrote:*   

> However, did you try the reverse engineered open source driver for nvidia cards? It has xrandr support for multiply monitors and you don't have to use TwinView.

 

Twinview and xrandr work very similarly. And the two displays limit isn't in software, it's in hardware. So xrandr won't help there. The only advantage nouveau has over nvidia is ZaphodHeads. But considering the Xinerama limitations, that's not really much.

Edit: Ok, nvidia supports Zaphod mode too, though I don't think they call it that. I don't have my nvidia laptop with me right now, so I can't play around with it. But that seems to be the best option here - Zaphod with the nvidia driver. This means separate displays (you can move the mouse between them, but not apps). If you need one big display and don't mind the performance hit, you can stitch the Zaphod displays together with Xinerama.

Edit2: Well, well, the latest nvidia beta (302.07) supports xrandr 1.2 and 1.3 !!

----------

