Xinerama, nVidia, Triple-head xorg problems
 

I just got a third monitor at work. I had everything working great with three workspaces, but I now need to be able to move windows between monitors. I enabled Xinerama because I couldn't figure out how to make Twinview do what I want, though I'm not opposed to changing to it.

The current status is this. . . everything works. The problem I'm having is that it's not stable. If I move a window from one monitor to another, I get an X server lockup. The mouse still works, but I can't interact with any windows. I can even keep typing in the window I'm already in, but I can't activate any controls, click on other windows or the current one, or alt+tab out. I can, however, ctrl+shift+1 to a console and +7 back into X. I can't use gdm-restart to reload X, but I can ctrl+alt+backspace to kill it.

Other strange symptoms that may or may not be relevant, but came up at the same time:
1) on my second and third monitors, scrolling is VERY slow in Firefox and a few other applications
2) When xscreensaver comes on, it is set to fade to black. After turning on Xinerama, only the primary screen fades, the second and third do not.
3) After a crash, Firefox insists on opening on a monitor other then were I click on it. This makes me move to another window, wich seems to cause another crash.

Actually, it seems like moving windows between displays causes the crashes sometimes, or even all the time. Of course, as I said before, this is the reason I set it up in the first place. . .



I don't know if it's a problem with my xorg.conf, but that's my first theory. Sooo. . . here's my xorg.conf :)


Also, my Xorg.0.log:

Hi,

I'm not expert, but since day one of my experience with dual monitor setups especially with nix, I've noticed a few things that get overlooked quite often.

First thing to note and address before we try to go anywhere with this is that the previous configuration and the new configuration are needed to compare what's changed to see where problems *should* lie.

I notice something right away: You added a new monitor while you don't speak of having added a new graphics card.

Given this, I jump to the immediate conclusion that you've have two cards with 1 monitor each up until now. This leads me to look for a few things.

So, heading down to your log we notice that you have two monitors on the device at PCI:1:0:0: being a GeForce 7300 SE if our feedback is correct. This is enough to make me jump to look a something that's commonly missed.

Even if you have something in that generally family, the max resolution of the card is 2560x1600 which most people either don't understand or don't realize.

Just in case you don't know that means are total screen drawn with that 1 videocard can only be a combined 2560 pixels wide by 1600 pixels tall.

So screen 0 width plus screen 1 width must add up to no more than 2560. Also, neither of their heights must be over 1600. If having trouble imagining, measuring across both monitors with an imaginary pixel ruler couldn't be more than 2560 horizontally, and from the top to the bottom of the lowest point of either couldn't be past 1600.

Your two monitors attached to the 7300 SE are running at 1360x768 and 1440x900 according to your log. This gives us a total screen size on that videocard of 2800x900. This is bigger than the supported resolution.

This needs to be confirmed inside X if it's available and immediately remedied if these are the resolutions that are actually being applied. I don't know what this does to the cards technically, but you are well beyond the specs.

Unfortunately this may cause you to have to reconsider your whole layout as far as your hardware is concerned. This may or may not be the stem of all your problems, I have no way of knowing, but it came to attention and I would suggest taking care of that to prolong your hardware even if it isn't the case.

Lenard

P.S. you have two modules not being found on the system from your config file, "type1" and "record"

Perhaps I should clarify. I've been using dual-head on this display for a year. I added the third monitor a month or so ago. All was working well with independent X screens and without Xinerama. All I'm trying to do is make Xinerama work without killing my desktop.

In dual-monitor mode, I was using two monitors (the Viewsonics) on the 7300. I added the 6200 when I added the third monitor. I moved the analog-connected viewsonic to the 6200 and attached the Sharp to the analog port on the 7300 and left a Viewsonic on the DVI port on the 7300.

Everything worked as seperate X screens pre-Xinerama. Other than the problems with stability, the only problem appears to be with GL on the two viewsonics.

Thanks

3 or 4 monitors with nVidia stuff.. xorg.conf
 

Interestingly, I use (some of) the same video cards as the OP, and I also use Xinerama. I have 3 monitors running much of the time, though at the moment I took one off to connect it to another machine temporarily.
I went through some head crashing getting the finer details sorted out, but now it works perfectly with 3 or 4 monitors.
Note that I use CRT's (until I someday hopefully get a whack of LCD's :)) but in case it helps you, I am posting here my xorg.conf. Maybe something will pop out at you.. I see some small differences, but with X, it's the small details that kill an otherwise good setup. There are some helpful comments to myself at the start of the file. I hope you get it sorted :)

Sasha

Well, I made some changes to my xorg.conf, mostly adding option lines that you had and I didn't, thank you. No change to performance and other issues. I haven't had any crashes, but they aren't that predictable.

Any other suggestions?

Actually, yes, now that I look again at your log file..

The nVidia driver uses its own DRI implementation, so you do not need to specify the DRI module, nor the DRI section at the end of the file. Perhaps that is causing some problems, using the external DRI..
Remove that. I will look some more, and if there's something else, I'll offer my thoughts.

EDIT: In 2 of your lines "OPTION USEDISPLAYDEVICE" you specify "CRT-0" but you should be specifying "DFP-0".

EDIT: Also, according to the EDID, the valid horizSync range for your CRT-0 is 31.0 - 69.0, so you should edit the line in the "Monitor" section for that device, and correct the range.

PS - for all practical purposes, a default depth of 24bit color is overkill. At least for the time being, try using 16bit as the default color depth instead. You won't notice a difference, and it may speed things up.

Finally, please tell us what version of the nvidia driver you are using currently (EDIT: I see it is 14.09), and whether you have considered trying some other version? Maybe one version older might avoid a bug of some kind in the driver.

Incidentally, what kind of motherboard is this?
Have you tried the nvnews forums for suggestions?

Good luck :)

Stabbing here, but, for the sake of it....

Can you install mesa-utils if you don't have it and run:

if we have a yes, how about trying
from a term window and watching it's output while placing it on different screens

If GLX is failing on other windows, it could be from the kernel module being built from 1.0-7174
Please check the nvidia-kernel-* packages for their version. 1.0-7174 doesn't support GLX with Xinerama: http://www.nvnews.net/vbulletin/arch...p/t-62973.html

And of course, I would recommend following Sasha's advise on cleaning up settings. Most of the failovers that allow X to manage to start with a bad config induce very very strange bugs from the accounts I've read.