X misdetects LG Flatron F700B as 775FT - 50hz refresh rate

littleweseth · 2007-11-03 16:03:07

Hi;

I acquired a LG Flatron F700B today and hooked it up (nice, sharp picture, much nicer to stare at than my venerable, fuzzy Benq V772.) The issue here is that according to nvidia-settings, my computer thinks that this is a LG 775FT.

This wouldn't be so bad, but there's a distinct difference in specifications between the two monitors - the F700B does max. 1280x1024 @ 85Hz, but the 775FT (which X seems to think I have) only does 1280x1024 @ 60Hz. Interestingly, xrandr reports the maximum resolution as 1280x1024 @ 50Hz.

As you can imagine, 50/60Hz makes ones eyes bleed... I've tried editing the Monitor section in xorg.conf with appropriate sync ranges taken from the monitor specs at link [1], but apparently new versions of X just go ahead and autodetect the monitor anyway, which is actually working against me here (autodetection is nice, but only when it detects the Right Thing.)

nvidia-settings only lets me push the monitor up to 60hz.

Does anyone have any suggestions as to how I can 'persuade' X that my monitor Really Can Do 1028x1024 @ 85hz? I'm tempted to take a cudgel to it and see if it plays nice

Cheers;
-lws

[1] : http://www.superwarehouse.com/LG_Electr … /ps/141938

fwojciec · 2007-11-03 16:22:14

Nvidia actually uses refresh rate to report a completely different property, something to do with twinview mode and compatibility with TVs and such - that's why you shouldn't really worry about what xrandr says... You can use nvidia-settings to see what the actual refresh rate is, it most certainly isn't 50hz. If that figure bothers you you can add something like this to the device section in xorg:

Option "DynamicTwinView" "False"

This will not actually change how the image is displayed but it will make xrandr return the actuall refresh value.

This is what nvidia manual has to say about this:

Option "DynamicTwinView" "boolean"
Enable or disable support for dynamically configuring TwinView on this X screen. When DynamicTwinView is enabled (the default), the refresh rate of a mode (reported through XF86VidMode or XRandR) does not correctly report the refresh rate, but instead is a unique number such that each MetaMode has a different value. This is to guarantee that MetaModes can be uniquely identified by XRandR.
When DynamicTwinView is disabled, the refresh rate reported through XRandR will be accurate, but NV-CONTROL clients such as nvidia-settings will not be able to dynamically manipulate the X screen's MetaModes. TwinView can still be configured from the X config file when DynamicTwinView is disabled.
Default: DynamicTwinView is enabled.

littleweseth · 2007-11-04 00:59:15

Thanks, but I just found the mode information display in the monitor's OSD - which I guess is the final verdict on what the monitor is actually pushing. It's 1280x1024 @ 60hz indeed.

Still not 85hz by any stretch of the imagination, though

Edit : Incidentally, that's an AWESOME avatar. It's drawn on the back of my bike helmet now

Last edited by littleweseth (2007-11-04 01:00:10)

Arch Linux

#1 2007-11-03 16:03:07

X misdetects LG Flatron F700B as 775FT - 50hz refresh rate

#2 2007-11-03 16:22:14

Re: X misdetects LG Flatron F700B as 775FT - 50hz refresh rate

#3 2007-11-04 00:59:15

Re: X misdetects LG Flatron F700B as 775FT - 50hz refresh rate

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