Comment 39 for bug 830949

I have tested with a Dell mini 9 hooked on an external 1600x1200 monitor.

The display resolution of the dell mini 9 is 1204x600

When I use the gnome display setting and I try to set a configuration that is not supported (size is too high), I am being warned to choose a lower resolution for the external monitor. For a system, like the Dell mini 9, this works fine as I can't expect such a system to have the resources to drive Unity on an external monitor with 1600x1200 resolution.

I then used xrandr to configure the displays. With xrandr i got similar results as mentioned in #33. I could get Unity to work with xrandr provided the external display resolution isn't too high. Xrandr worked fine for an external resolution of 1024x768. For an external resolution of 1152x864, the rendering of the display was very slow, which suggest a software mode. Note that gnome display setting prevent me from setting an external resolution of 1152x864.

From a user perspective, the preferred display configuration tool is the gnome display setting. From my experience, it produces the expected results.

As for using xrandr directly and activating the "Copy to Texture" plugin in Compiz, this solution cannot work with Unity for external resolution that are too high. As state in #32, it would only work fine with standalone Compiz. Unity has no support for the "Copy to Texture" plugin and cannot be expected to work.

I think the "Copy to Texture" plugin should be deactivated and users should use the gnome display setting as there preferred display setting tool.

Xrandr, does the job of configuring the display resolution. But without any knowledge of the desktop environment memory requirements it cannot check the ability of the system to support a certain resolution. Yet, it is very useful tool as a low level display configuration utility.