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Changing the refresh rate in fedora 2

Hi all,
I could not find refresh rate in Display settings.
How can i change the refresh rate on Linux(Fedora Core 2)?

Thanks in advance.

e-tsik

Hi :-)

Vertical refresh rate is one of the frequent pains i get from X, specifically when I try to use it with an old screen.

The easiest way to change the refresh rate I know is to edit the file
/etc/X11/xorg.conf

Look up the word: VertRefresh
Modify the higher value to you monitor's maximum vertical refresh rate.
These settings apply when you restart the X server (CTRL-ALT-BackSpace should do the trick)

(example)
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Sony CPD-100SX"
DisplaySize 280 210
HorizSync 30.0 - 65.0
VertRefresh 50.0 - 120.0
Option "dpms"
EndSection

Another thing you can do while you're editing the file is to modify the maximum screen resolution. Look below in section "Screen" - you can modify the resolution modes there:
Section "Screen"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
Modes "1024x768" "800x600" "640x480"
EndSubSection
EndSection

You can switch resolution modes with CTRL+ALT+Kepad+ and CTL+ALT+Keypad-

Enjoy!

ASKER CERTIFIED SOLUTION

Karl Heinz Kremer

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manish_regmi

ASKER

Thanks for your input.

But i want to make the refresh rate exactly 100HZ.
Like in windows we do from display properties.

Manish

Karl Heinz Kremer

This means that you have to deal with the modline configuration manually. Look into the HOWTO I linked to.

SOLUTION

e-tsik

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manish_regmi

ASKER

Ok,
Now, i have generated the modline from the link you gave

For 800x600 at 100HZ, it gives,

////////////////////////////////////////////////////

Horizontal Resolution: 800
Vertical Resolution: 600

Vertical Refresh Rate: 100.00 Hz
Horizontal Refresh Rate: 63.83 KHz
Dot Clock Frequence: 68.94 MHz

# V-freq: 100.00 Hz // h-freq: 63.83 KHz
Modeline "800x600" 68.94 800 840 928 1080 600 600 602 638

/////////////////////////////////////////////////

Now should i change the "modes"(or tell me which line to change) line in x.org to above value(Modeline "800x600" 68.94 800 840 928 1080 600 600 602 638 ).
But will it harm? I am sure it(800x600 at 100HZ) works in windows.

Manish

manish_regmi

ASKER

hi e-tsik,
I will try that and return tomorrow.

Thanks

Karl Heinz Kremer

If you already have a modline for 800x600 in your config file, just comment out the existing line and add the new one right after the original one (which now is commented out). Give it a try. A multi-sync monitor should not get damaged by this. Don't do something like this with fixed frequency monitors!
If it does not work, you can alwasy stop X by using Ctrl-Alt-backspace

manish_regmi

ASKER

hi khkremer and e-tsk,
I will try the suggestions and return tomorrow.

Thanks
Manish

manish_regmi

ASKER

hi khkremer and e-tsk,
Both of your suggestions worked. But e-tsk's idea does not work for all values as he said.

Thanks for your help