I recently aquired a new desktop for work which came with a 17″ Philips LCD screen. Given that I work from home and I already owned a 17″ LCD the scene was set for a nice dual-head setup, or so I thought. Having two LCD monitors side by side, I wanted them both to be running on DVI. This was not to prove an easy task.

The first hurdle was finding a video card with Dual-DVI output for a reasonable price. This was made even harder by the fact that I was originally looking for a AGP card to avoid having to upgrade the entire motherboard. Eventually we gave up on this option and I ended up getting an HP dc7600 mini tower with a PCI-e slot to use for my desktop. We also ordered a Power Color card based on the Radeon X1300 chipset to satisfy the Dual-DVI requirement.

Unfortunately when the machine arrived (around the end of March) I discovered that the X1300 was not yet supported by the open source X.org drivers and, even worse, there was no support for it in the latest fglrx release from ATI either! This was sloppy checking on my part really. I’ve become so used to hardware “just working” thanks to Ubuntu that I didn’t even consider that the card might not be supported. I filed a support request with ATI asking when support for the X1300 was expected and received the standard “Linux isn’t supported, not aware of any upcoming revisions, we’ll support it when we get around to it” style response. Eventually we found an Radeon X850 based Dual-DVI PCI-e card for around twice the price of the X1300 and ordered that. I limped along with a single screen using the VESA driver until the card arrived.

Initial impressions with the X850 card were not promising. Although it is supported by the radeon driver in X.org 7.0 there seems to be a bug that prevents it from working correctly in Dual-head mode. There are numerous tickets in the X.org bugzilla and the problem appears to be solved if you use DVI+VGA, but its still broken for DVI+DVI unfortunately. Next step was to try the fglrx drivers to see if I could get Dual-head working with them. More problems! fglrx doesn’t play nicely with Xen (I run my desktop in a Xen dom0 with other testing domains (for sid, etc) in domU’s). After reverting back to the standard Ubuntu kernel (eg. no Xen) I’ve managed to get a nice Dual-DVI Dual-Head setup working with the X850.

However, in the process of installing the fglrx drivers I discovered that there had been a new release made on the 12th of April that among other changes added support for the X1300 chipset!!! Needless to say I’m not particularly impressed with the response from ATI’s helpdesk, given that only one week prior, they had disclaimed any knowledge of when support for the X1300 chipset would be available. As it turns out, its a bit of a non-issue anyway as I couldn’t make the X1300 work properly in a Dual-DVI setup. The secondary screen suffered all sorts of corruption and ghosting that I couldn’t work out how to remove. Running the second screen in VGA mode (via a DVI-VGA adaptor) was fine, but with a drop in quality due to the VGA connection.

So after several months of waiting, almost a day of configuration twiddling and the loss of Xen. I finally have a Dual-head, DVI based desktop setup. Its very nice, but the cost is certainly high. I can’t believe that Dual-DVI doesn’t seem to be widely used, am I really that fussy about my monitors?

Now that I’ve had to give up Xen, I’m trying to get VMware setup to do the job, but I’m already running in to problems there. VMware refuses to use LVM devices for raw disk access and the LD_PRELOAD solution provided by vmware-bdwrapper is not playing nicely with dapper’s multiarch setup at the moment. Hopefully with another days worth of twiddling I can get it working!