[clug] Dual Monitors with Thinkpad T410

Jeremy Kerr jk at ozlabs.org
Tue Jul 19 23:30:13 MDT 2011

Hi Lana,

> Basically just looking for anyone who has done anything like this
> before with a T410 (or similar) running Linux. I'm really not sure if
> the graphics card will be able to handle it.

While it's not comprehensive, the following should give you a good idea
if it's possible.

At the terminal, do a `xrandr`, and check that you have an output for
both connectors. They'll probably be listed as DVI1 & DVI2, but *may*
have other names, like DP1/DP2.

If that's ok, do a `xrandr --verbose`, and look at the 'CRTCs'
information for each of the DVI outputs. A CRTC is the source of the
display data, and your video device probably has more than one. The
"CRTCs" numbers indicate which of the CRTCs can be connected to this
output. If you want different images on each display, you'll need to
have different a CRTC on each output. For example, if you have something

DVI1 disconnected (normal left inverted right x axis y axis)
	CRTCs:      0 1

DVI2 disconnected (normal left inverted right x axis y axis)
	CRTCs:      0 1

- then you can connect CRTC 0 to one output, and CRTC 1 to the other, so
this *should* work. But then, actually plugging something in is always
going to be more reliable.

Hope this helps,


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