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Linuxhelp _ Hardware Support _ Refresh Rate Locked!

Posted by: caffeinbot Feb 14 2004, 09:51 PM

Hey guys, I have a problem with my refresh rate. It seems that it cannot go above 75hz in linux, although i know for a fact that it can go to 85 at 1280x1024. I have mangaed to do so both in linux, and in windows. but for some reason the last few times ive tried installing linux on this computer, it seems that it wont go higher that 75hz. Ive configured my xfree86 file to allow higher rates, but to no avail. this isn't just an ati issue either, i had the same problem with nvidia's geforce mx 440.
any ideas would be appreciated.

Posted by: hughesjr Feb 15 2004, 07:27 AM

The 2 key things to look at are the driver being used by the video card and the scan and refresh rates for the monitor in the file:

/etc/X11/XF86Config (or XFConfig86-4 ... if XF86Config-4 is present, it will be used ... if not, XF86Config will be used)

The first thing to check is the listed rates, for my NEC Multisync they are as follows:

HorizSync 31.0 - 82.0
VertRefresh 55.0 - 120.0

Get the specs for your monitor ... should be available on the website or from the technical manual...and change the numbers if required.
(If you are using SUSE, you can't change these in the file itself, but you have to use sax2)

The other thing to look at is the Display driver:

Driver "ati"

Posted by: caffeinbot Feb 16 2004, 09:52 PM

yea those are all set correctly...

Posted by: hughesjr Feb 16 2004, 10:08 PM

I have a Nvidia FX 5200 (128mb card) and an NEC Multisync E1100 (21") Monitor and I can display 1024x768 at 85Hz, but not anything higher than that (at 85Hz)

Posted by: caffeinbot Feb 17 2004, 04:27 AM

I understand that some monitors have the ability to take on different refreshrates, and have certain limitations, but my monitor is running at 85 hz under win2k (ew i know) but it fails to do so in linux.
I wonder what the real problem is...

Posted by: hughesjr Feb 17 2004, 06:17 AM

The problem is that XFree86 doesn't think it can display that mode given the card and the monitor specs ...

One thing you can try (if you know the amount of RAM on your video card) is to add the line:

VideoRam 65536
that is the amount for 64Mb

What is your Monitor?

Posted by: Corey Feb 26 2004, 02:19 PM

If you know that you're monitor can indeed handle 1280x1024@85, then there are ways that you can push your monitor to that. Rather then totally repeat the entire process, I'll post a link to the Gentoo forum thread that discusses it:

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