DynamicTwinView and randr

[arundel]

hi there,

with DynamicTwinView set to false in xorg.conf i'm getting the following xrandr results:

Screen 0: minimum 320 x 175, current 1680 x 1050, maximum 1680 x 1050
default connected 1680x1050+0+0 (normal left inverted right) 0mm x 0mm
1680x1050 60.0*
1152x864 75.0
1024x768 85.0 75.0 70.0 60.0 87.0
800x600 85.0 75.0 72.0 60.0 56.0 70.0 65.0
640x480 85.0 75.0 73.0 60.0
400x300 85.0 75.0 72.0 60.0 56.0
1400x1050 75.0 60.0
1280x1024 85.0 75.0 60.0
1280x960 85.0 60.0
960x720 75.0 60.0
928x696 75.0 60.0
896x672 75.0 60.0
832x624 75.0
720x400 85.0
700x525 75.0 60.0
640x512 85.0 75.0 60.0
640x400 85.0
640x350 85.0
576x432 75.0
512x384 85.0 75.0 70.0 60.0 87.0
416x312 75.0
360x200 85.0
320x240 85.0 75.0 73.0 60.0
320x200 85.0
320x175 85.0

if DynamicTwinView is set to true (default) i'm getting:

Screen 0: minimum 320 x 175, current 1680 x 1050, maximum 1680 x 1050
default connected 1680x1050+0+0 (normal left inverted right) 0mm x 0mm
1680x1050 50.0*
1152x864 51.0
1024x768 52.0 79.0 80.0 81.0 82.0 83.0
800x600 53.0 87.0 88.0 89.0 90.0 91.0 92.0 93.0 94.0 95.0
640x480 54.0 99.0 100.0 101.0 102.0 103.0 104.0
400x300 55.0 109.0 110.0 111.0 112.0
1400x1050 56.0 75.0
1280x1024 57.0 76.0 77.0
1280x960 58.0 78.0
960x720 59.0 84.0
928x696 60.0 85.0
896x672 61.0 86.0
832x624 62.0
720x400 63.0
700x525 64.0 96.0
640x512 65.0 97.0 98.0
640x400 66.0
640x350 67.0
576x432 68.0
512x384 69.0 105.0 106.0 107.0 108.0
416x312 70.0
360x200 71.0
320x240 72.0 113.0 114.0 115.0
320x200 73.0
320x175 74.0

is this to be expected? i'm running NVIDIA-FreeBSD-x86-190.40 on 9-CURRENT.

cheers.
alex

[zander]

Yes, see e.g. http://us.download.nvidia.com/freebsd/185.18.36/README/chapter-07.html:

Why is the refresh rate not reported correctly by utilities that use the XRandR X extension (e.g., the GNOME "Screen Resolution Preferences" panel, `xrandr -q`, etc)?


The XRandR X extension is not presently aware of multiple display devices on a single X screen; it only sees the MetaMode bounding box, which may contain one or more actual modes. This means that if multiple MetaModes have the same bounding box, XRandR will not be able to distinguish between them.

In order to support DynamicTwinView, the NVIDIA X driver must make each MetaMode appear to be unique to XRandR. Presently, the NVIDIA X driver accomplishes this by using the refresh rate as a unique identifier.

You can use `nvidia-settings -q RefreshRate` to query the actual refresh rate on each display device.

This behavior can be disabled by setting the X configuration option "DynamicTwinView" to FALSE.

For details, see Chapter 12, Configuring TwinView.

[arundel]

thanks a lot for the hint. now i've set DynamicTwinView to false. however `nvidia-settings -q RefreshRate` says:


Attribute 'RefreshRate' (otaku:0.0; display device: DFP-0): 59,95 Hz.
'RefreshRate' is an integer attribute.
'RefreshRate' is a read-only attribute.
'RefreshRate' is display device specific.
'RefreshRate' can use the following target types: X Screen, GPU.

and `xrandr -q` says:

Screen 0: minimum 320 x 175, current 1680 x 1050, maximum 1680 x 1050
default connected 1680x1050+0+0 (normal left inverted right) 0mm x 0mm
1680x1050 75.0* 60.0
1400x1050 75.0 60.0
1280x1024 85.0 75.0 60.0
1280x960 85.0 60.0
1152x864 75.0
1024x768 85.0 75.0 70.0 60.0 87.0
960x720 85.0 75.0 60.0
928x696 75.0 60.0
896x672 75.0 60.0
832x624 75.0
800x600 85.0 75.0 72.0 60.0 56.0 70.0 65.0
720x400 85.0
700x525 75.0 60.0
640x512 85.0 75.0 60.0
640x480 85.0 75.0 73.0 60.0
640x400 85.0
640x350 85.0
576x432 75.0
512x384 85.0 75.0 70.0 60.0 87.0
416x312 75.0
400x300 85.0 75.0 72.0 60.0 56.0
360x200 85.0
320x240 85.0 75.0 73.0 60.0
320x200 85.0
320x175 85.0

so...is my display running at 75 mhz or 59,95 mhz?
alex

[zander]

it's running at 59,95Hz. XRandR reports the front-end timings, nvidia-settings the back-end timings. It seems both 60Hz and 75Hz were validated as back-end timings, but e.g. the Force Full GPU Scaling setting forced the driver to use the display's native timings.