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acceptable hsync and vrefresh?

Posted: Sat Jul 09, 2005 9:52 am
by ryan
Hi,

I have a T42 2378-DXU (15" 1400x1050 IPS).

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I can't find acceptable horizontal sync and vertical refresh numbers. I've checked manuals, the IBM site, thinkwiki, and Google.

At linux-laptop.net I found 2 mentions of the hsync and vrefresh for the 2378-FVU (14" 1400x1050 monitor).
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The first one says:
HorizSync: 31.5 - 90.0
VertRefresh: 59.0 - 75.0

The second one says:
HorizSync: 30.0 - 94.0
VertRefresh: 50.0 - 160.0

The first one's numbers looked more precise to me (31.5) and less likely to be crazy (50-160!?), so I used the first one's.

Is this a mistake? Will my monitor blow up / burn out?

Posted: Mon Jul 18, 2005 11:12 am
by phyast
Sync rates don't apply to LCD displays, only to CRT displays. You don't need any lines in the Screen section of your X configuration file that refer to H or V sync rates.

chad

Posted: Mon Jul 18, 2005 11:42 am
by doppelfish
phyast wrote:Sync rates don't apply to LCD displays, only to CRT displays.
<nitpick>
They do apply to LCDs, except that an extremly high refresh rate usually doesn't buy you any advantage as it does for a CRT. A vertical refresh rate of 60Hz is usually good enough on a LCD (and often also the maximum), while a CRT going at anything below 75Hz is a surefire way for a headache of the worst kind.
</nitpick>
phyast wrote:You don't need any lines in the Screen section of your X configuration file that refer to H or V sync rates.
This is still correct, tho', since the TP's LCDs talk DDC (or maybe even DDC2) to the card, so that the simple Mode entry in the Screen section will suffice. If you drive an external monitor, especially an older model, you might still enjoy the extraordinary fun that is to be had with writing ModeLines. If the external monitor also talks DDC, you're home free, tho'.

cheers,
-- fish