Arch Linux

Johnnio

Member

From: Glasgow, Scotland

Registered: 2007-08-26

Posts: 10

Xorg and Horizontal Sync

Hi. I'm having a bit of trouble configuring X. According to the Wiki I need to find out my Horizontal Sync and Vertical Refresh, but the problem is I don't how to find it out. It says if I use the wrong values I could fry my monitor... so I'm not really tempted to try random values. I've read my laptops manuals but it says nothing about my monitor specs (my manuals just tell me how to setup Windows, FAQ, troubleshooting etc). I did a bit of Googling and came across a program called 'xresprobe' but I can only find a Debian package of it, and I'm not sure if Arch supports this type of packaging.

How do all the 'newbie friendly' distributions get my monitor information? Should I perhaps install Ubuntu and use its xorg.conf? I'm currently dual booting Windows and Arch. Maybe Windows will have a file which has my monitor information?

Much help appreciated. Thanks.

dante4d

Member

From: Czech Republic

Registered: 2007-04-14

Posts: 176

Re: Xorg and Horizontal Sync

According to the xorg.conf man page:

HorizSync horizsync-range
    gives the range(s) of horizontal sync frequencies supported by the monitor. horizsync-range may be a comma separated list of either discrete values or ranges of values. A range of values is two values separated by a dash. By default the values are in units of kHz. They may be specified in MHz or Hz if MHz or Hz is added to the end of the line. The data given here is used by the Xorg server to determine if video modes are within the specifications of the monitor. This information should be available in the monitor's handbook. If this entry is omitted, a default range of 28-33kHz is used.
VertRefresh vertrefresh-range
    gives the range(s) of vertical refresh frequencies supported by the monitor. vertrefresh-range may be a comma separated list of either discrete values or ranges of values. A range of values is two values separated by a dash. By default the values are in units of Hz. They may be specified in MHz or kHz if MHz or kHz is added to the end of the line. The data given here is used by the Xorg server to determine if video modes are within the specifications of the monitor. This information should be available in the monitor's handbook. If this entry is omitted, a default range of 43-72Hz is used.

I agree that the monitors handbook is a good place. If you don't have it, you can probably find pdf version or something on manufacturers pages. Try that.

Good luck

Johnnio

Member

From: Glasgow, Scotland

Registered: 2007-08-26

Posts: 10

Re: Xorg and Horizontal Sync

I love you man! I thought Xorg would have configured the .conf itself using those options. I'll try that now. I should check the man pages more often. Again, thanks.

Last edited by Johnnio (2008-05-06 16:18:01)

MONODA

Member

Registered: 2008-02-09

Posts: 256

Re: Xorg and Horizontal Sync

install hwd and then run : hwd -s
this will show you your hardware info in a basic way, you should be able to find what you are looking for there.

hokasch

Member

Registered: 2007-09-23

Posts: 1,461

Re: Xorg and Horizontal Sync

xrandr is also quite good with this.

Johnnio

Member

From: Glasgow, Scotland

Registered: 2007-08-26

Posts: 10

Re: Xorg and Horizontal Sync

Thank you very much for all your help, I really appreciate it. I'm currently posting on Arch. Just need to configure everything. Again thanks.

dante4d

Member

From: Czech Republic

Registered: 2007-04-14

Posts: 176

Re: Xorg and Horizontal Sync

hwd -s and xrandr are better solution I agree

Last edited by dante4d (2008-05-06 20:00:14)

synthead

Member

Registered: 2006-05-09

Posts: 1,337

Re: Xorg and Horizontal Sync

hwd -s and xrandr are better solution I agree

I didn't know about xrandr!  Very useful, thanks a lot for recommending it.  I didn't know hwd -s listed monitor refresh rates either.

Isn't it true that modern xorg drivers automatically set up scan rates by itself?  In all of the xorg configs I've written via xorgconfig, I've set the maximum rates for everything and it has always worked.