# Changing Monitor Refresh Rates ????

## Cappy

Is there any way to actually change the refresh rate. The problem is, my monitor is capable of 100 Hz at 1024x768. My vid card supports this also. I know X probes the monitor to find the optimal refresh rate but it defaults to 85 Hz....which isn't sufficient. I use 100 Hz in Windows. Anyway...the problem is, for some reason, anything below that, the display has an annoying left to right....almost like a fast vibration or shimmy. It does this in Windows also at 85 Hz...100Hz solves this. It's not a flicker.....like with a low refresh rate, and it's almost unoticeable....but when you spend alot of time behind the monitor it is...and very annoying. I was just wondering if there was anyway to bypass this and force a 100hz refresh rate. I've been using linux for a while and it is like this in every distro.....detecting a max of 85 hz instaed of 100hz. I've also tried creating custom modelines in XF86Config....but every attemp  seems to distort the screen size and possition terribly (beyond what can be adjusted using xvidtune) It would be greatly appreciated if someone with some knowledge on successfully doing this could help me out  :Smile: 

Thanks

Cap

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## antik

 *Cappy wrote:*   

> Is there any way to actually change the refresh rate. 
> 
> Thanks
> 
> Cap

 

Try Colas XFree Modeline Generator.

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## Cappy

No luck....same deal. I tried several different variations using that tool, and stiil wind up with a terrible small offset display....although it was at 100Hz. I've used several other similiar tools with no results. I know if I can have a perfectly useable dislpay in Windows using 1024x768 @100Hz, there should be a way to do it in Linux also.

Cap

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## Malakin

You can use xvidtune to tweak the modeline.

Edit: sorry, didn't notice you already mentioned this ;) Modelines always work for me, not sure what else to suggest. Maybe try a slightly different resolution like 1152x864 with a modeline and see how it works out.Last edited by Malakin on Fri Apr 04, 2003 12:22 am; edited 1 time in total

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## Cappy

 *Quote:*   

> I've also tried creating custom modelines in XF86Config....but every attemp seems to distort the screen size and possition terribly (beyond what can be adjusted using xvidtune)

   :Wink: 

Cap

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## antik

 *Cappy wrote:*   

>  *Quote:*   I've also tried creating custom modelines in XF86Config....but every attemp seems to distort the screen size and possition terribly (beyond what can be adjusted using xvidtune)  
> 
> Cap

 

Sometimes I make X config file with RedHat. They have much better support for different videocards and monitors.

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## cyrillic

Look at the "Monitor" section of your /etc/X11/XF86Config file :

```
Section "Monitor"

        Identifier   "Monitor0"

        VendorName   "Monitor Vendor"

        ModelName    "Monitor Model"

        Option       "DPMS"

        HorizSync    30-107

        VertRefresh  100

EndSection
```

By using a single value rather than a range for "VertRefresh", you can force any refesh rate that your monitor/videocard support.

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## Cappy

Tried that....the X-server just bombs out. I looked at the log, but nothing of any value there. I'm might be on to something though...gonna give it a try.  :Smile: 

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## Cappy

Success !!!   :Smile:   I used the tool posted above....but It needed some serious number hacking to get a "useable" modeline manipulated. Once in range for xvidtune, I had to manipulate it an read the onscreen video mode output from the monitor to get it to match what it was reading in Windows. Then use the monitor screen adjustment to shift it into place. The result: I'ts only 0.1 khz off HorizSync from my Windows install, 100hz VertRefresh on the nose, and my display in Window is only a few pixels off (from messing with the monitor controls themselves), which I just used my vid card GUI to correct the slight picture offset. I also places the Option "DDCMode" "off" under my gfx adapter, it suposedly defaults to off when not present....so I really don't know if it helped. I never really gave it THIS much effort in any other distro I used....but since I started using Gentoo....theres no going back to any other....so I wanted things "just right"  :Smile:  You know what I mean    :Wink:  .

Thanks everyone  :Smile: 

Cap

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## Cappy

Success !!!   :Smile:   I used the tool posted above....but It needed some serious number hacking to get a "useable" modeline manipulated. Once in range for xvidtune, I had to manipulate it an read the onscreen video mode output from the monitor to get it to match what it was reading in Windows. Then use the monitor screen adjustment to shift it into place. The result: I'ts only 0.1 khz off HorizSync from my Windows install, 100hz VertRefresh on the nose, and my display in Window is only a few pixels off (from messing with the monitor controls themselves), which I just used my vid card GUI to correct the slight picture offset. I also places the Option "DDCMode" "off" under my gfx adapter, it suposedly defaults to off when not present....so I really don't know if it helped. I never really gave it THIS much effort in any other distro I used....but since I started using Gentoo....theres no going back to any other....so I wanted things "just right"  :Smile:  You know what I mean    :Wink:  .

Thanks everyone  :Smile: 

Cap

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