Running Ubuntu 8.04 (beta) at Work

As an experiment today I tried installing the Ubuntu 8.04 beta on my work PC. I work for a very large commercial company and don’t personally know of anyone who has tried such a thing before, so I thought I might as well give it a go.

Here are some highlights of the 5 or 6 hours I spent on this today:-

Dual Screen

Most of my time was spent mucking about trying to get my dual screens setup to work. Something that is supposed to be easier in 8.04.

Ubuntu detected my video card fine (an on-board Intel 945G, quite standard for a work PC) and initially set me up with one monitor fine. Screen redraws were fast and Compiz was running pretty well.

But both monitors were showing the same image…

So I jumped to the new 8.04 Screen Resolution dialog and had a looksy. Sure enough it thought I had 2 monitors. It had also correctly decided that 1600×1200 was the resolution of choice. But where was the option to run a second desktop on screen #2?

And why was my xorg.conf nearly empty?

The answer (after quite a bit of research): X.Org 7.3 and XRandR.

As of 7.3, X.Org decides to wherever possible keep your xorg.conf brief. So much so that if you are having display issues the recommendation is to delete your xorg.conf file and restart X. Wow. The only downside being if you want to tweak just one parameter, erm, how do you do that?

XRandR, or X Resize and Rotate, replaces a plethora of dynamic display utilities and basically does just resize and rotate your X display or displays.

Right. So what about that Screen and Graphics dialog from Gutsy, aka displayconfig-gtk? It used to allow me to configure multiple displays the way I wanted. Oddly it’s now in the menus under Applications->Other. It’s an Application now? (Looks like this has since been removed – there’s now no menu item for it at all!)

Right anyway, so I trundled through and configured my screens using displayconfig-gtk, hit the Test button and wow, what an ugly garbled display I had on screen #1 and screen #2 just went black.

Fiddled with the settings some more and managed to get screen #1 looking okay but nothing on screen #2.

Reset my xorg.conf back to default.

Read somewhere that adding

SubSection "Display"
Virtual 3200 1200
EndSubSection

should solve the problem (3200×1200 being the bounding box resolution of my 2 screens).

It worked! But screen draws were reeealllyyy sllloooww.

A quick scan through the xorg log file and hmm, this message

Cannot support DRI with frame buffer width > 2048

In other words, the driver was telling me my virtual desktop size (3200 pixels wide) was too big for the hardware to support. Odd, I’ve had this working before I thought.

I finally discovered that one of the caveats of XRandR is that it:

…hardware does not support unlimited coordinates. For instance, Intel boards up to i945 only support 2048 pixels in each direction. If you enable a larger virtual screen, DRI will be disabled and some problems may appear.

In other words: Even if your hardware is capable of handling two high-res displays, XRandR won’t be your friend unless your hardware is equally capable of running a single really really high-res display. For this reason I must say that I don’t think XRandR is ready for the big time and Ubuntu in some cases needs to know to fall back to other technologies.

The (only?) solution? Manually configuring Xinerama. Something I don’t mind doing but enough to put most new Linux users off the whole thing.

And the caveat: No Compiz.