dual-head (xinerama mode) graphics card recommendations

Hello everybody

I’ve been running 11.1 (64bit) on my Pentium D for a while now, and have just started using dual monitors, with an Nvidia 8600GT.

I’ve been having little (and not-so-little) irritations and problems (I am suspecting due to the drivers) - Alt-Tabbing between apps will sometimes freeze X, and (this bothers me even more) if I am dragging a window from one monitor to another, the 2nd monitor will blank out until I let go of the mouse button (i.e. I have to “guess” where the window will be the first time I drag it over; works ok when I’m moving it within the 2nd monitor)

It’s not a hardware fault because when I did a test dual-boot with Windows, it works fine. So, I’m now in the market for a new PCIe graphics card.

Would it start a flamewar if I asked which is more trouble-free, ATI or Nvidia? Any recommendations for a card? (I’m thinking practically everything on the market is “better” than my current card already, so low-to-mid-tier cards are fine, I don’t want/can’t afford a super-expensive card)

I have the GT8600GTS and I haven’t experienced the problems you describe so I don’t think it’s the card. There must be some other problem to get those symptoms.
Having said that, I’ve given up on dual monitors under Linux for now but only because I needed one of them rotated and that can only be done using two separate X screens which creates all kinds of other issues (no moving of windows between screens, etc). If you don’t need to rotate a screen, why use Xinerama at all - it does not support 3D acceleration with Compiuz or Kwin - and not Twinview?

yeah, since it’s working in Windows I figured there’s nothing wrong with the card hardware itself, but I was wondering about how good/bad the Nvidia drivers are (closed source and so a black box, yes?), and if there’s any sort of consensus as to which cards/series/manufacturer’s cards gave the most trouble-free experience on openSUSE.

Are you on the 64 bit version of 11.1 ?

When I google I get all sorts of opinions, but nobody really talks about multi-monitor setups.

I mention Xinerama because that’s the option that SaX2 gave me - what do you mean re: the other options?

Thanks!

I’m on 32-bit 11.1.
The NVIDIA drivers are generally quite good, except they don’t support RandR which is annoying. I’ve heard all sorts of things, good and bad, so I’m not sure it’s worth switching.
Better to try and sort it out. First I’d try to avoid Sax2 and start with nvidia-settings, NVIDIA’s own utility, to write a new xorg.conf. Make sure anything written by Sax2 that duplicates what nvidia-settings writes is deleted.
In nvidia-settings (make sure to run it as su, btw) untick the Xinerama box, and configure both monitors as Twinview which gives you one desktop covering both monitors. See how you go and come back if there’s still a problem.

build6 wrote:

> When I google I get all sorts of opinions, but nobody really talks
> about multi-monitor setups.

I have currently an “old” nVidia 7600 GS card with dual dvi-d working and
setup with nvidia driver (proprietary one) in dual-screen layout. It works
very well under opensuse 10.3 and kde 3.5.10.

This card has passive refrigeration (no fan) so no noise comes from it which
is a plus (newly vga cards tend to be quite noisy) :slight_smile:

I also would go for nvidia card.

Greetings,


Camaleón

gminnerup wrote:

> The NVIDIA drivers are generally quite good, except they don’t support
> RandR which is annoying. I’ve heard all sorts of things, good and bad,
> so I’m not sure it’s worth switching.

Where did you heard nvidia driver is not supporting randr? :wink:

At least for rotation seems to be possible using it…

Chapter 17. Using the XRandR Extension
http://tinyurl.com/muofad

Greetings,


Camaleón

It doesn’t support RandR 1.2. With dual monitors, you can only rotate both through Twinview, or one through Xinerama, but that disables compositing so no Compiz/Kwin…
RandR enables you to rotate only one of two monitors while having 3D acceleration but the NVIDIA binary drivers won’t play. NVIDIA have promised support for RandR 1.2 but not, so far, delivered.

gminnerup wrote:

> It doesn’t support RandR 1.2. With dual monitors, you can only rotate
> both through Twinview, or one through Xinerama, but that disables
> compositing so no Compiz/Kwin…

Rotation it should work by enabling the right option in xorg.conf file:


X.Org version X11R6.8.1 contains support for the rotation component of the
XRandR extension, which allows screens to be rotated at 90 degree
increments.

The driver supports rotation with the extension
when ‘Option “RandRRotation”’ is enabled in the X config file.


At least this is what it reads from nvidia “Readme” file for the latest
drivers :-?

> RandR enables you to rotate only one of two monitors while having 3D
> acceleration but the NVIDIA binary drivers won’t play. NVIDIA have
> promised support for RandR 1.2 but not, so far, delivered.

Btw, what currently vga drivers have full support for randr 1.2 extention? I
mean, intel, radeonhd, ati, nv… :-?

Greetings,


Camaleón

Yes, rotation works (done it myself that way) but only for both monitors together with Twinview. Or even just one, but then only with separate X servers (no moving of windows between them).
Don’t know which others support 1.2 as I haven used them but I think ATI and Intel do, but I may be wrong there.

Hi everyone, thanks for all the helpful comments, much appreciated.

I managed to discover what the problem was - in SaX2, during the monitor configuration dialogs, I had left “enable DPMS” on. In an experiment I disabled it (it was enabled by default) and now I don’t have the same screen-blanking problem (the freeze-on-alt-tab I haven’t tested yet… I’ve become conditioned to not using alt-tab anymore!). I guess the blanking was due to power management issues (?!).

I only discovered that because I couldn’t get sudo nvidia-settings to work :-P, it kept complaining about the control display being undefined, even though $DISPLAY was set (and I didn’t find the info in --help very helpful…), so I gave up, reinstalled the Nvidia drivers with one-click, and then ran SaX2 -r again.

And, as a summary, most posters Feel Pretty Good about Nvidia card support in openSUSE; if I retire this card I suppose I will get another Nvidia!

Thanks everybody

Hrm. I just tried nvidia-settings again, this time I forgot to use “sudo”, and it worked, which seems counterintuitive to me. Anyways clicking around it looks like I am in “TwinView” mode, although SaX2 didn’t say anything about that (I suppose TwinView is Nvidia’s way of calling it, while Xinerama is a more canonical X11 term that SaX2 uses instead?).

ok… my application switcher problem hasn’t been solved. about 90% of the time, when I switch applications, I’ll be “stuck” in the switched and never return to the desktop. Mouse is responsive but everything else is frozen. I cannot force restart X with Ctrl-Alt-Backspace, but I can shell in from another box to kill/restart X manually. Oh well.

If you use nvidia-settings without su, it doesn’t write to xorg.conf (speaking from memory here but I think that’s true) so whatever settings you make are lost on restart.
No, Xinerama and Twinview are quite different. Again, if I remember correctly, Xinerama allows you to move between separate screens, whereas Twinview actually presents both as one screen to xorg. In any case, Xinerama is pretty outdated now, quite slow and doesn’t support Compiz so it’s much better to use Twinview if you don’t need to rotate one of the monitors (or if you want to rotate both).
To repeat, my advice from bitter experience is to use either Sax or nvidia-settings but not both to write to xorg.conf, and of the two nvidia-settings is much more reliable.

You need to use Ctrl-Alt-Bcksp twice to restart xorg…

heh, I think for this kind of thing, it’s safe to assume that people will try it more than once…

I’m the kind of guy who uses up quite a lot of ammo (compared to my buddies) for the same targets, so yeah, I did bang on the key-combo a couple of times. No response, it was a serious freeze!

hrm. nivida-settings for me launches a dialog, when I have X already running, in which it identifies things running in TwinView mode. When I’m in runlevel 3 and use SaX2, it identifies me as being in xinerama mode - and compiz definitely works with it (since I didn’t use nvidia-settings before, only SaX2). there doesn’t seem to be any wierd “collisions” in xorg.conf

all the window effects works for me, it’s only the Application Switchers that barf and freeze up on me. Anyways, this doesn’t look like a “hardware” problem per se, so I’m gonna post a new thread in another section…

last note re: hardware, all I can say is, you guys all seem to really like Nvidia :slight_smile:

I repeat: Twinview and Xinerama are not the same thing. The only way to establish what you’re actually running is to look at your xorg.conf. If Compiz works, you’re not, I repeat not, using Xinerama. Full stop.

Just to make this absolutely clear, with dual-head NVIDIA you have three choices in nvidia-settings (just stay clear of Sax, it doesn’t understand dual monitors):

  1. two X screens: you can do anything you like (rotate each monitor separately using RandR, 3D acceleration) but you can’t move windows between the screens.
  2. Twinview: you can have 3D acceleration and one desktop stretching over both monitors, but you can’t rotate just one of them (it’s both or neither).
  3. Xinerama: you can do everything you want but you can’t have 3D acceleration.

As you don’t want rotation and, I assume, want to move windows freely across both monitors, and have Compiz (or Kwin), your only option is Twinview. To configure Twinview, ignore Sax and use nvidia-settings in superuser mode (when it comes to writing xorg.conf, don’t “merge” the new settings into the existing xorg.conf in case that has been contaminated by Sax2).

Now all this is the result of hard experience with NVIDIA and dual monitors. It might not solve all your issues (some of which don’t seem to have anything to do with NVIDIA/X) but it will eliminate those related to dual-head configuration.