Thinkpads Forum

I have a T500 with switchable graphis (intel on-board graphics + ATI) and an external monitor connected to the DVI output. So far, the only way to get my external monitor working is enable the discrete (ATI) graphics in the BIOS. If I boot using the internal intel graphics, the external screen remains blank. In this case, xrandr -q doesn't even show DVI-0. Also, I've been unable to use the external monitor via display port. The disadvantage of using the discrete graphics is that the T500 produces much more heat and fan noise this way.

Has anybody got an external monitor work with the internal graphics?

This is the output of xrandr using the discrete graphics on Ubuntu 9.10:

~$ xrandr -q
Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 3600 x 1200
DVI-0 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 546mm x 352mm
1920x1200 60.0*+
1600x1200 60.0
1680x1050 59.9
1600x1000 60.0
1280x1024 75.0
1280x960 60.0
1152x864 75.0
1024x768 75.0 60.0
832x624 74.6
800x600 75.0 60.3
640x480 75.0 59.9
720x400 70.1
LVDS connected (normal left inverted right x axis y axis)
1680x1050 60.1 + 50.1
1400x1050 60.0
1280x1024 59.9
1440x900 59.9
1280x960 59.9
1280x854 59.9
1280x800 59.8
1280x720 59.9
1152x768 59.8
1024x768 59.9
800x600 59.9
640x480 59.4
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
VGA-0 disconnected (normal left inverted right x axis y axis)

Don't quote me on this but I think the external monitor ports (VGA, DisplayPort, DVI) are connected directly to the discrete graphics in models with switchable graphics. To get a picture on them with Intel graphics you would need an Intel-only T500.

Not going to happen. The digital ports can only be used with the discrete card.

http://www-307.ibm.com/pc/support/site. ... R-70495#e2

IIRC the integrated card isn't even attached to the digital ports.

You could try tinkering with ACPI and fan control if the noise is a bother...otherwise you could always fall back to using integrated graphics and VGA.

Superego wrote:The digital ports can only be used with the discrete card.

What a stupid design. So I'd be better off with an intel only T500?

At least, is there a way to lower the power consumtion of the discrete graphics to the level of the intel graphics on Linux?

What a stupid design. So I'd be better off with an intel only T500?

I don't know if I'd call it stupid; there are probably some difficult hardware issues to overcome. Maybe Intel's chipset limited Lenovo to picking only one GPU for the digital ports? Also, Lenovo is marketing the switchable graphics as a mobile workstation. I guess the thinking is that the ATI gpu is for when you don't worry about battery life (e.g. at your desk where your external monitor is) and the integrated gpu is for when you're out and about. Not that that helps your situation...just trying to understand Lenovo's reasoning.

Anyway, yes an all-intel (i.e. integrated graphics) will run the digital ports.

Regarding power consumption, I'd start by looking around Thinkwiki (try here). If you use the open-source ATI driver you'll have to edit your Xorg.conf to enable Xorg's power-saving features; if you use the proprietary ATI driver there is an option for setting different power modes (more info on thinkwiki for both of these options).

You could also try some kind of fan control software to help reduce the noise. Again, thinkwiki is your friend.