On Sun, Sep 19, 2010 at 05:28:28PM +0200, Elio Fabri wrote:
> Hi, I own an old notebook (ASUS A2 series) with installed Red Hat 9 and 
> SL 5.4.
> With SL I have problems driving external monitors, whereas Red Hat never 
> gave problems.

x.org went through some changes in how it talks to some chipsets,
and how it detects monitor hotplugging.  Unfortunately, RHEL5 was
frozen in the middle of this transition, and some chipsets suffer,
such as that in my older Thinkpad T30.  

One painful method that usually works on the T30 is to reboot with
the projector attached.  Before SL5, hotplug would Just Work.  I
hope SL6 will Just Work, like recent versions of Ubuntu do.

With my newer T60, and the fglrx driver, I can enable the screen
with xrandr .  I have a 2048x1536 screen, and I need to set it to
1024x768 mode for the 1024x768 projector to work right with that
driver (which only does windowing, not resizing, and only does
mouse pan).

The next step, after you get some functionality, is dealing with
some kinds of video, which may render as a black rectangle on the
projector, depending on the driver.  After that, rendering speed.
I use lots of full screen flash animations in my web-based
presentations ( see http://server-sky.com/wydiwys ) and spend a
lot of time tweaking compression and frame rates.

Since RHEL (and therefore SL) is targeted for servers, insufficent
effort was spent making video on laptops work right.  Still, it
can be fixed, with research and tweaking.   The other advantages 
of SL make up for the extra laptop setup time.

Keith

-- 
Keith Lofstrom          [log in to unmask]         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs