12.10 Refresh rate not available

**cstreet** · November 26th, 2012

Hi

I am not sure if this is the right place to post this but here goes:

I have recently installed Ubuntu 12.10 in dual boot mode to a Dell Precision T3600 work station, everything seems to be working fine apart from I can not get the refresh rate to go
above 85Hz on the monitor, the monitor is a Mitsubishi Diamond Pro 2070SB
( http://www.mitsubishielectric.com.au/2345.htm ), I know the monitor can support a refresh rate of 120Hz at higher resolutions as I have gotten this to work under Windows 7, I should also mention that I need the monitor to run at 120Hz in order to run a experiment using mathlab & psytoolbox so this is not merely a whim but a necessity.

I have installed the latest drivers from the nvidia.com for the Quadro 5000 & they seem to working without issue, so I don't think this is anything to do with the video card as far as I can tell.

I've tried to manually add the needed refresh rate at the current resolution using the following commands according to https://wiki.ubuntu.com/X/Config/Res...d_resolutions:

sudo cvt 1600 1200 120

which produced:
# 1600x1200 119.82 Hz (CVT) hsync: 154.45 kHz; pclk: 343.50 MHz
Modeline "1600x1200_120.00" 343.50 1600 1736 1912 2224 1200 1203 1207 1289 -hsync +vsync

which I then used with xrandr:

sudo xrandr --newmode "1600x1200_120.00" 343.50 1600 1736 1912 2224 1200 1203 1207 1289 -hsync +vsync

This seemed to work up until I tried to add the mode:

sudo xrandr --addmode DVI-I-0 "1600X1200_120.00"
which resulted in the following error messages:
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 18 (RRAddOutputMode)
Serial number of failed request: 33
Current Serial number in output stream: 34

Any help would be very much appreciated, as I've been banging my head against this problem for days now

.

PS: I've attached a zip containing the output of lshw for the system in question I don't know.

**Wim Sturkenboom** · November 26th, 2012

According to the specs of the monitor (see the user manual), the max refresh rate at 1600x1200 is 109Hz (not 120Hz); this might be the cause of the error. I wonder, by the way, how Windows manages to do it 'right'.

Code:

640 x 480 @ 50 to 160 Hz
800 x 600 @ 50 to 160 Hz
all modes listed.
1024 x 768 @ 50 to 160 Hz
1280 x 1024 @ 50 to 127 Hz
1600 x 1200 @ 50 to 109 Hz .................... NEC-Mitsubishi Electronics Display cites recommended resolution a 85 Hz for optimal display performance.
1800 x 1350 @ 50 to 98 Hz
1800 x 1440 @ 50 to 92 Hz
1856 x 1392 @ 50 to 95 Hz
1920 x 1440 @ 50 to 92 Hz
2048 x 1536 @ 50 to 86 Hz

Out of curiosity, what kind of experiment (if you're allowed to tell)?

**cstreet** · December 17th, 2012

Hi

Thanks for the help, sorry that I haven't replied sooner been a bit busy and yes you were right about the max refresh rate at 1600x1200, as for windows I think it was running at 1152x864 which is probably why it was able to do 120Hz refresh rate.
I did manage to get it working eventually by creating a xorg config file with the correct Hsync & Vsync for the monitor.
I then added the modeline that was generated by calling cvt with the parameters 1280 1024 120 to the Monitor section, I also added metamodes Option to the Screen section.
I think it was the "PreferredMode" that caused X to operate at my desired settings but I am not entirely sure it may have been the "metamodes" bit or a combination of the two.
Anyway long story short bit of a faff but got it working in the end.
I've attached my xorg file so anybody else who has the same problem has at least a rough idea of where to begin.

Regards and Seasons Greetings