LinuxQuestions.org
Go Job Hunting at the LQ Job Marketplace
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Distributions > Slackware
User Name
Password
Slackware This Forum is for the discussion of Slackware Linux.

Notices

Reply
 
Search this Thread
Old 05-03-2008, 08:44 PM   #1
Woodsman
Senior Member
 
Registered: Oct 2005
Distribution: Slackware 14.1
Posts: 3,482

Rep: Reputation: 536Reputation: 536Reputation: 536Reputation: 536Reputation: 536Reputation: 536
Validating Vertical Screen Refresh Rate


How do I do this?

KDE reports a screen refresh rate, but nowhere else can I find this information to validate what KDE reports. I ask because when I use the nv drivers, KDE reports 75 Hz and when I use the proprietary nvidia driver, KDE reports 50 Hz. This latter number bothers me because the monitor only supports 56 to 75 Hz. That range is explicitly defined in my xorg.conf. Therefore either the nvidia drivers are ignoring this directive or KDE is incorrect.

I don't know whether the values reported are correct and I'd like a second or third method to determine the frequency.

Edit: I'm using Slackware 12.1, KDE 3.5.9, kernel 2.6.24.5, nvidia drivers 169.09. Motherboard is Asus M2NPV-VM with built-in video chip (nForce 430/MCP51). Monitor is a 17" Samsung SyncMaster 712N LCD, native resolution is 1280x1024.

Last edited by Woodsman; 05-03-2008 at 09:42 PM.
 
Old 05-03-2008, 09:44 PM   #2
IsaacKuo
Senior Member
 
Registered: Apr 2004
Location: Baton Rouge, Louisiana, USA
Distribution: Debian 4.0 Etch
Posts: 1,349

Rep: Reputation: 49
My experience is that the nvidia official driver does indeed ignore what you set in xorg.conf, unless you use a "strange" custom modeline name. For example, if you use a resolution named "1280x960", it doesn't matter even if you specify a custom Modeline. The nvidia driver will ignore your custom Modeline and it will ignore your VertRefresh option. But if you use a resolution named "1280x960foobar", it will accept your custom modeline.
 
Old 05-03-2008, 10:07 PM   #3
Smedley
Registered User
 
Registered: Apr 2008
Distribution: Slackware
Posts: 74

Rep: Reputation: 15
Quote:
Originally Posted by Woodsman View Post
How do I do this?

KDE reports a screen refresh rate, but nowhere else can I find this information to validate what KDE reports. I ask because when I use the nv drivers, KDE reports 75 Hz and when I use the proprietary nvidia driver, KDE reports 50 Hz. This latter number bothers me because the monitor only supports 56 to 75 Hz. That range is explicitly defined in my xorg.conf. Therefore either the nvidia drivers are ignoring this directive or KDE is incorrect.

I don't know whether the values reported are correct and I'd like a second or third method to determine the frequency.

Edit: I'm using Slackware 12.1, KDE 3.5.9, kernel 2.6.24.5, nvidia drivers 169.09. Motherboard is Asus M2NPV-VM with built-in video chip (nForce 430/MCP51). Monitor is a 17" Samsung SyncMaster 712N LCD, native resolution is 1280x1024.
On a side note, there are known issues with your kernel and the nVidia drivers. Check out the nvnews forums.
 
Old 05-03-2008, 10:48 PM   #4
Franklin
Senior Member
 
Registered: Oct 2002
Distribution: Slackware, WinXP, Windows 7
Posts: 1,253

Rep: Reputation: 55
All the monitors I have used have on screen utilities for brightness, contrast, etc.
One of these is usually a display of the current resolution and refresh rate. If this is available, I would believe what that tells me over anything else.
 
Old 05-03-2008, 10:53 PM   #5
mRgOBLIN
Slackware Contributor
 
Registered: Jun 2002
Location: New Zealand
Distribution: Slackware
Posts: 999

Rep: Reputation: 227Reputation: 227Reputation: 227
Try running the "nvidia-settings" application see what it reports.
 
Old 05-04-2008, 02:30 PM   #6
Woodsman
Senior Member
 
Registered: Oct 2005
Distribution: Slackware 14.1
Posts: 3,482

Original Poster
Rep: Reputation: 536Reputation: 536Reputation: 536Reputation: 536Reputation: 536Reputation: 536
Quote:
My experience is that the nvidia official driver does indeed ignore what you set in xorg.conf
I'll keep that in mind. This is my first box with the nvidia drivers.

Quote:
My experience is that the nvidia official driver does indeed ignore what you set in xorg.conf
Possibly. However, the problem existed in Slackware 12.0 (kernel 2.6.21.5) too.

Quote:
All the monitors I have used have on screen utilities for brightness, contrast, etc. One of these is usually a display of the current resolution and refresh rate. If this is available, I would believe what that tells me over anything else.
I would love to learn how to access those controls on my monitor. The manual that came with the monitor is awful (I have no other complaints about the monitor). I'm sure there is a secret combination to make the buttons display the information you describe, but I have not found that secret. The menu button does nothing on my monitor. I would like to adjust the contract.

Quote:
Try running the "nvidia-settings" application see what it reports.
I did that and the refresh rate is reported as 75 Hz.

I also tried xvidtune, which reported 75 Hz.

The problem seems to be xrandr. The KDE Control Center extracts information through krandrtray, which is a front-end to xrandr. When I run xrandr --query I see the same weird frequency results as in KDE. xrandr reports only 50 and 53 Hz for 1280 x 1024 display.

Can anybody else verify that xrandr is incorrectly displaying the refresh rate? Or offer troubleshooting tips why xrandr reports what I see?
 
Old 05-04-2008, 03:19 PM   #7
Franklin
Senior Member
 
Registered: Oct 2002
Distribution: Slackware, WinXP, Windows 7
Posts: 1,253

Rep: Reputation: 55
Does your model come with six buttons on the bottom right side of the monitor?

If so, the button all the way on the right when pushed may give you that info.

1. Picture Brightness Contrast
2. Color Color Tone Color Control Gamma
3. Image Coarse Fine Sharpness H-Position V-Position
4. OSD Language H-Position V-Position Transparency Display Time
5. Setup Image Reset Color Reset
6. Information

Code:
steve@sundog:~$ xrandr
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1440 x 1440
VGA connected 1440x900+0+0 (normal left inverted right x axis y axis) 408mm x 255mm
   1440x900       59.9*+   75.0
   1280x1024      75.0     59.9
   1440x900@75.0   75.0
   1280x960       59.9
   1152x864       75.0     74.8
   1024x768       75.1     70.1     60.0
   832x624        74.6
   800x600        75.0     60.3     56.2
   640x480        75.0     60.0
   720x400        70.1
steve@sundog:~$
xrander states 59.9, my monitor states 60Hz

I'm using intel (not nvidia - sorry) graphics (intel i915) LG Flatron Wide LCD


HTH

Last edited by Franklin; 05-04-2008 at 03:22 PM.
 
Old 05-04-2008, 04:04 PM   #8
digger95
Member
 
Registered: Oct 2007
Location: Indiana, PA
Distribution: Slackware 14
Posts: 330

Rep: Reputation: 45
Mine seems to be okay woodsman.

Xrandr reports 85Hz and my monitor reports 87Hz:

Code:
slacker[~]$ xrandr
Screen 0: minimum 640 x 480, current 1024 x 768, maximum 1280 x 1024
default connected 1024x768+0+0 (normal left inverted right) 0mm x 0mm
   1024x768       85.0* 
   1280x1024      60.0     85.0  
   800x600        85.0  
   640x480        85.0
 
Old 05-04-2008, 04:10 PM   #9
speck
Member
 
Registered: Nov 2001
Location: California
Distribution: Slackware 14.1
Posts: 289

Rep: Reputation: 60
xrandr is incorrect for me as well. My monitor (19in 1280x1024 LCD) display screen reports 60 (which is correct), not 50.

Code:
xrandr
Screen 0: minimum 320 x 240, current 1280 x 1024, maximum 1280 x 1024
default connected 1280x1024+0+0 0mm x 0mm
   1280x1024      50.0* 
   1024x768       51.0     56.0  
   800x600        52.0     57.0     58.0     59.0     60.0  
   640x480        53.0     63.0  
   1280x960       54.0  
   1152x768       55.0  
   800x512        61.0  
   640x512        62.0  
   576x384        64.0  
   512x384        65.0     66.0  
   400x300        67.0     68.0     69.0  
   320x240        70.0
 
Old 05-04-2008, 04:16 PM   #10
digger95
Member
 
Registered: Oct 2007
Location: Indiana, PA
Distribution: Slackware 14
Posts: 330

Rep: Reputation: 45
I was just perusing the manual for your monitor:

712N User Manual

You're right, it's a bit hard to follow, but you should definitely be able to access your monitor's current refresh rate, etc. I'm just not very good with manuals I'm afraid. Perhaps someone more literate than I can help.

Dig
 
Old 05-04-2008, 04:42 PM   #11
T3slider
Senior Member
 
Registered: Jul 2007
Distribution: Slackware64-14.1
Posts: 2,330

Rep: Reputation: 771Reputation: 771Reputation: 771Reputation: 771Reputation: 771Reputation: 771Reputation: 771
I'm still on Slackware 12.0 and xrandr reports 50...
Code:
t3slider@linux:~$ xrandr
Screen 0: minimum 320 x 240, current 1680 x 1050, maximum 1680 x 1050
default connected 1680x1050+0+0 0mm x 0mm
   1680x1050      50.0*    55.0
   1280x1024      51.0     61.0
   1024x768       52.0     65.0     66.0
   800x600        53.0     69.0     70.0     71.0     72.0     73.0
   640x480        54.0     77.0     78.0     79.0
   1600x1024      56.0
   1440x900       57.0     58.0
   1400x1050      59.0     60.0
   1280x960       62.0
   1280x720       63.0
   1152x864       64.0
   832x624        67.0     68.0
   800x512        74.0
   640x512        75.0     76.0
   576x432        80.0
   512x384        81.0     82.0     83.0
   416x312        84.0
   400x300        85.0     86.0     87.0     88.0
   320x240        89.0     90.0     91.0
...while nVidia settings reports 59.95 Hz (and my monitor reports 60 Hz). KDE reports 50 Hz as well (but it probably gets its info from xrandr). It appears that there is (and has been for a while) a bug in xrandr that *may* falsely report the refresh rate. I would trust the proprietary nVidia driver's settings tool over any run-of-the-mill KDE tool, but I could be wrong.
 
Old 05-04-2008, 05:31 PM   #12
Woodsman
Senior Member
 
Registered: Oct 2005
Distribution: Slackware 14.1
Posts: 3,482

Original Poster
Rep: Reputation: 536Reputation: 536Reputation: 536Reputation: 536Reputation: 536Reputation: 536
Quote:
You're right, it's a bit hard to follow, but you should definitely be able to access your monitor's current refresh rate, etc. I'm just not very good with manuals I'm afraid. Perhaps someone more literate than I can help.
Funny --- about an hour after posting, I got fed up and started exercising the hell out of the menu button. Eventually the menu appeared.

Eventually I figured out how to navigate the menu and yes, like all those blinking clocks on VCR and DVD players, there is a reason why hardware engineers receive the criticisms they do. I just hate anything that is designed to be multi purpose using only a few buttons. A nightmare!

Anyway, eventually I got to the information menu option and confirmed my monitor was running at 75 Hz.

Quote:
It appears that there is (and has been for a while) a bug in xrandr that *may* falsely report the refresh rate.
So xrandr remains suspect, at least here on my installation. Based upon my monitor specs, I expect the two numbers from xrandr to be 60 Hz and 75 Hz, not 50 and 53.

Quote:
xrandr is incorrect for me as well. My monitor (19in 1280x1024 LCD) display screen reports 60 (which is correct), not 50.
I wonder whether there is a calculation error/bug in the source code for 1280x1024 displays?
 
Old 05-04-2008, 05:50 PM   #13
T3slider
Senior Member
 
Registered: Jul 2007
Distribution: Slackware64-14.1
Posts: 2,330

Rep: Reputation: 771Reputation: 771Reputation: 771Reputation: 771Reputation: 771Reputation: 771Reputation: 771
Quote:
Originally Posted by Woodsman
I wonder whether there is a calculation error/bug in the source code for 1280x1024 displays?
Or maybe 1280x1024 and above, since I have the same (harmless) issue with a 1680x1050 display (though Franklin has a 1440x900 display, from the looks of it, and it is accurate).
 
Old 05-04-2008, 06:07 PM   #14
Franklin
Senior Member
 
Registered: Oct 2002
Distribution: Slackware, WinXP, Windows 7
Posts: 1,253

Rep: Reputation: 55
Quote:
Originally Posted by T3slider View Post
Or maybe 1280x1024 and above, since I have the same (harmless) issue with a 1680x1050 display (though Franklin has a 1440x900 display, from the looks of it, and it is accurate).
But I'm not using nVidia.

Back when I was (the good ol' days) I remember an option that I had to use in xorg.conf to make certain that the monitor info was not polled. This needed to be done so that I could use the DisplaySize option to set a custom DPI for my fonts. I'm curious whether either of you with bogus xrandr data are using that or a similar option that might be giving you incorrect readings.

Just a random thot.
 
Old 05-04-2008, 06:21 PM   #15
ErV
Senior Member
 
Registered: Mar 2007
Location: Russia
Distribution: Slackware 12.2
Posts: 1,202
Blog Entries: 3

Rep: Reputation: 62
Quote:
Originally Posted by Woodsman View Post
How do I do this?
On newer/better monitors refresh rate should be visible in on-screen menu (monitor's menu).
You can also launch nvidia-settings and check refresh rate (since this is known NVidia problem).
You can also check refresh rate visually - I simply can't look at 60 Hz and below for a long time, so you'll clearly see the difference between 75Hz and 50HZ.
Also, if CRT monitor is not "smart", and you'll try to use values above/below supported it should go out of sync (horizontal/vertical synchronization), which will be clearly visible. If this doesn't happen, this means that refresh rate is near or inside supported range. Can't gurantee this, though...
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Vertical Refresh Rate shawniecas Linux - General 27 08-17-2007 04:56 PM
How to find my horizonal and vertical refresh rate girlintrouble Linux - Hardware 4 05-16-2006 03:54 PM
Vertical refresh rate, horizontal sync rate. NomDeGuerre Linux - Newbie 7 10-07-2005 02:36 AM
Screen with multicolored vertical lines / Refresh rate very low wittyguysuku Fedora 2 08-24-2005 01:54 AM
Horizontal and vertical refresh rate johannes Linux - Laptop and Netbook 3 10-31-2003 05:44 AM


All times are GMT -5. The time now is 11:55 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration