Hi All,
I'm normally pretty adept at figuring things out but this one has me stumped. Googling has sent me down many alleys most of them blind.
I have 2 identical machines one with Ubuntu 10.04 the other with Windows 7 Ultimate. The run through a KVM switch to the same monitor using their on-board Nvidia Geforce 6100 graphics adapters. The monitor is a cheapo AOC 24" TFT panel which is adequate for my purposes, mainly general office stuff, accounting, surfing, email etc. This monitor is weird in that it requires a refresh rate of 61Hz rather than a standard 60Hz to give a steady display at its native resolution 1920x1200.
In the Nvidia control panel in Windows it is easy to set a custom refresh rate, so no problem and a nice display. Ubuntu 10.04 however using the current proprietary driver from the Ubuntu repositories does not have the same facility, unusable display so dropping back to a non native resolution for the monitor is the only way to use the GUI.
Back in the day you used to be able to hack your /etc/X11/xorg.conf file and insert a new modeline to facilitate this but as far as I can tell this has no effect with the current incarnation of the Xorg server. I suspect the monitor is not outputting its configuration, data or something. I have removed the KVM switch and the problem still remains so it isn't that blocking the data from the monitor reaching the driver.
Can anybody enlighten me on how to manualy do this and get the proper 1920x1200 resolution working @ 61Hz rather than the sole 60Hz option allowed by the Nvidia control panel?
Cheers, BJ
Both your computers should be using the video timings from the monitor's EDID, which could look something like this (the preferred mode of an inexpensive Acer AL2416W): Detailed Timing 1920x1200x24@60 =============== Pixel Clock : 154000000 hActive : 1920 hBlanking : 160 hSyncOffset : 48 hSyncPulseWidth: 32 hBorder : 0 hBackPorch : 80 hFrontPorch : 48 vActive : 1200 vBlanking : 35 vSyncOffset : 3 vSyncPulseWidth: 6 vBackPorch : 26 vFrontPorch : 3 vBorder : 0 flags : 0x1a Progressive Normal display; no stereo syncSignal1 = 3 = DigitalSeparate syncSignal2 = 1 = HSyncPos:VSyncNeg ImageSize : 518x324mm (24.1" diagonal, 16:10 ratio)
The vertical refresh rate is calculated as PixelClock / (hTotal * vTotal) which on my monitor is 154000000 / (2080 * 1235) = 59.95Hz, so there is a small amount of rounding involved when it claims it is 60Hz.
If you can post a dump of your monitor's EDID with read-edid, I'll have a stab at guessing where the 61Hz figure is coming from.
Regards, Tim.
On 28 September 2010 12:12, John Woodard mail@johnwoodard.co.uk wrote:
Hi All,
I'm normally pretty adept at figuring things out but this one has me stumped. Googling has sent me down many alleys most of them blind.
I have 2 identical machines one with Ubuntu 10.04 the other with Windows 7 Ultimate. The run through a KVM switch to the same monitor using their on-board Nvidia Geforce 6100 graphics adapters. The monitor is a cheapo AOC 24" TFT panel which is adequate for my purposes, mainly general office stuff, accounting, surfing, email etc. This monitor is weird in that it requires a refresh rate of 61Hz rather than a standard 60Hz to give a steady display at its native resolution 1920x1200.
In the Nvidia control panel in Windows it is easy to set a custom refresh rate, so no problem and a nice display. Ubuntu 10.04 however using the current proprietary driver from the Ubuntu repositories does not have the same facility, unusable display so dropping back to a non native resolution for the monitor is the only way to use the GUI.
Back in the day you used to be able to hack your /etc/X11/xorg.conf file and insert a new modeline to facilitate this but as far as I can tell this has no effect with the current incarnation of the Xorg server. I suspect the monitor is not outputting its configuration, data or something. I have removed the KVM switch and the problem still remains so it isn't that blocking the data from the monitor reaching the driver.
Can anybody enlighten me on how to manualy do this and get the proper 1920x1200 resolution working @ 61Hz rather than the sole 60Hz option allowed by the Nvidia control panel?
Cheers, BJ
-
John Woodard -
Tim Green