Monitor frequency unclear, making noises

[trg818]

Dear forum,
I am somewhat confused about the configuration of my graphics card after having replaced my old openSUSE with Mint 12 (32-bit version). The most obvious problem is that always, a few minutes after booting and logging in, the monitor starts making a very high-pitched sound, and occasionally the screen image becomes fuzzy. If the session lasts longer, these symptoms disappear more or less quickly and completely, but nonetheless I find this a bit worrying, because it did not happen under openSUSE.
I suspected that it might have to do with the refresh rate. I do have the recommended drivers for my nVidia card (GeForce 6150 SE nForce 430) installed, and in the nVidia settings program the desired frequency of 85 Hz and resolution of 1240x768 appear correctly. My monitor is also correctly identified as a Samsung SyncMaster, although the exact type (757NF) is not given. However, inxi -G returns for the resolution 1240x768@50.0hz, and this is also what I see in the monitor preferences accessed via MATE's control center; here, the monitor is not recognized either, it appears as "Unknown Monitor", albeit with the right resolution. I have no possibility to ramp up the refresh rate there, because the range offered is only 50-55 Hz.
Furthermore, I observe that the xorg.conf file is practically empty, containing only a "Device" section with two default lines without any information.
So my question is: which settings are actually active, and do the high-pitched sound and the resolution/frequency problems have to do with each other or are they more likely independent? What can I do about this?
Thanks for any help,
Thomas

[richyrich]

the range offered is only 50-55 Hz.

I remember a machine like this, and 51 was actually 60, 52 = the next capable freq . . etc.

You may also want to try running the Nvidia Settings in superuser mode, and be sure to use the nvidia save feature before closing.

Code: Select all

gksu nvidia-settings

[trg818]

I don't see a possibility in the nvidia settings program to save the actual X server config. The only "Save" button I see there is for saving the settings of the program itself, but the file written when doing that seems to contain no information about, e.g., the refresh rate.

[richyrich]

[trg818]

Ah, that one! Time to clean my glasses, I guess.
Thanks, I did that now, and the xorg.conf is written accordingly - but it doesn't change anything. The monitor is still not recognized in the Monitor Preferences (even after rebooting), the offered refresh rate is still 50-55 Hz, and inxi still reports the frequency as 50 Hz (and that noise is still there). I wonder whether xorg.conf is read at all.
Thomas

[mank_in]

Maybe this helps : https://help.ubuntu.com/community/Nvidia

[AlbertP]

You can't trust inxi or Monitor Settings when using the official nVidia graphics driver. The only program that's able to handle refresh rates properly with this driver is nVidia's own X Server Settings app.

Edit. The version of nvidia-settings included with Mint 10 also had problems with the refresh rate of my monitor, defaulting to 60Hz while the screen supports 75. This is fixed in Mint 12's nvidia-settings; I'm not sure what about Mint 11 as I never used the official driver on my laptop with that Mint version.

Edit 2. The nvidia driver often does not show the type of the monitor, only the manufacturer, this also happens at me.

[mank_in]

You can't trust inxi or Monitor Settings when using the official nVidia graphics driver. The only program that's able to handle refresh rates properly with this driver is nVidia's own X Server Settings app

You are absolutely correct
in Nvidia setting my refresh rate is 85 Hz , but inxi -Gx show 50,1 Hz.

[trg818]

Ok, I guess I'll believe the data from the nVidia setup program then; the range for the refresh rate given in the xorg.conf written by it is correct, at least.
Thanks for your feedback,
Thomas

[AlbertP]

If that program still fails to set the proper refresh rate for your screen, you'd better uninstall the driver and go with Nouveau. On a GeForce 6150 3D will be slow but Gnome 3, Compiz, KWin or Google Earth should work.

[trg818]

If that program still fails to set the proper refresh rate for your screen, you'd better uninstall the driver and go with Nouveau. On a GeForce 6150 3D will be slow but Gnome 3, Compiz, KWin or Google Earth should work.

Ok, I have switched from the nvidia driver to nouveau now, and the Monitor Preferences and inxi now report resolution *and* frequency correctly and even recognize the manufacturer of my monitor (Samsung). Strange that the proprietary nvidia drivers cause such confusion. By the way, there is no xorg.conf anymore, it has apparently been removed when I deleted the nvidia driver.
Now, whether that resolves the problem with the noise I still have to see. When I reboot the machine tomorrow or so, I will find that out (as I said, the noise used to cease after a few minutes).
Thanks,
Thomas

[AlbertP]

You shouldn't need xorg.conf with the nouveau driver, unless you want to specify something that isn't properly auto-detected.