Arch Linux

G_Syme

Member

Registered: 2007-01-04

Posts: 83

Xorg resolution modes in xorg.conf vs. xrandr

I'm running Arch on a notebook with 1280x800 as native screen resolution (graphics card is an Nvidia 7200).
I've often had resolution problems regarding running games in fullscreen (Linux native & Wine) (starting from simple crashes over freezes up to reboots...), and am now inspecting my setup to look for possible reasons.

Now I've found out that the resolution modes in xorg.conf and those output by xrandr are mostly different:

xorg.conf (other depths have the same modes listed):

SubSection     "Display"
  Viewport    0 0
  Depth       24
  Modes      "1280x800" "1024x768" "1024x640" "960x600" "800x600" "800x500" "640x480"
EndSubSection

and the output of xrandr:

$ xrandr
Screen 0: minimum 320 x 240, current 1280 x 800, maximum 1280 x 800
default connected 1280x800+0+0 0mm x 0mm
   1280x800       50.0*
   1024x768       51.0
   800x600        52.0
   640x480        53.0     62.0
   960x540        54.0
   840x525        55.0     56.0
   800x512        57.0
   720x450        58.0
   680x384        59.0     60.0
   640x512        61.0
   576x432        63.0
   512x384        64.0
   400x300        65.0
   320x240        66.0

I've read often in the past that all modes which should be supported by Xorg have to be listed in xorg.conf, but from what I can tell from xrandr's output, it doesn't seem to be entirely the case.

Also, not all modes that xrandr lists really work. 1280x800, 1024x768 and 800x600 work definitely, but 640x480 (which is listed in both) remains in 4:3 aspect ratio and is not stretched to 16:10 like 1024x768 and 800x600, and other modes like 800x512 produce complete garbage, e.g. only part of the desktop is shown, screen refresh problems, the screen is shifted to the right up to the middle and contines from the left edge to the middle again , etc.

How am I to understand/fix this?

Any idea...?

---

The courageous enter dark caves alone.
The clever send in the courageous first.
The cleverest wait behind the clever.

G_Syme

Member

Registered: 2007-01-04

Posts: 83

Re: Xorg resolution modes in xorg.conf vs. xrandr

Seems that I'm coming closer to a conclusion:

When using the opensource nv driver (from package xf86-video-nv), I get a different list of supported video modes by xrandr:

$ xrandr
Screen 0: minimum 640 x 480, current 1280 x 800, maximum 1280 x 800
default connected 1280x800+0+0 0mm x 0mm
   1280x800       60.0*
   1024x768       60.0
   800x600        60.0
   640x480        60.0

Also to my pleasure, if I switch to 640x480, the mode is stretched from 4:3 to 16:10, so I can even see the complete screen on my 16:10 display. That's how it should be. Unfortunately, as the opensource nv driver doesn't offer 3D support, games are a no-go with this option.

I think I'll try the nouveau driver next.

---

The courageous enter dark caves alone.
The clever send in the courageous first.
The cleverest wait behind the clever.