2+ video cards should work as well in Ubuntu as Windows

Harry Coin hcoin at quietfountain.com
Fri Aug 5 17:33:24 UTC 2016


In a regression in recent years, Linux has failed to keep a feature well 
supported by its own earlier versions and all the various Windows OSen: 
to simulate one large display as well with two or three possibly 
dissimilar graphics cards as it does with one card with two or three or 
more outputs.  The cost of graphics cards with many outputs comes at a 
great price and performance hit over more cards with fewer outputs.  
This is becoming particularly pressing now that processors support 
on-die graphics adapters in addition to PCI express graphics slots 
supporting video adapters which almost never have the same architecture 
as the on-die graphics.

The arrival of pre-supposed support for compositing has ended the use of 
Xinerama, which at one time was the approach to this problem.

Many will be quick to note xrandr is 'the new way'.  For graphics cards 
hosting on the same card enough outputs for the entire system, it works  
(though I've yet to find a linux system on which dragging monitor icons 
when there are 3+ around the display configurator works).  The command 
line interface for xrandr is, well, its own entire body of obscure 
knowledge.  No real comparison to the simple Windows display dragging 
and sizing GUI.

As a work around, because try though I did for days of searching and 
attempting solutions to make it work all-Ubuntu: I'm forced to use a 
Windows front end which does a flawless job with two low/mid-market 
graphics cards acting as an X server to a headless Ubuntu back-end. It's 
ugly.  But without it no work happens.  All because Ubuntu can't manage 
more than one graphics card forming a large simulated single display as 
once it did.   Indeed there are vendor specific expensive workarounds: 
Nvidia's SLI + base Mosaic, Radeon / Quadro multi-headed 'whole 
paycheck' graphics cards, etc.  but Ubuntu shouldn't rely on such things 
when others do so well with what was installed-- over against Ubuntu 
upgrades that render a previously working system broken.

I urge whoever it is that sets goals in these matters to consider this.  
Thanks for reading!

Harry G Coin
Bettendorf, Iowa





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