[CentOS] additional X11 issues with CentOS 6.7

[Gordon Messmer]

On 08/17/2015 01:55 PM, Kay Schenk wrote:
> OK, I need to start with a basic "dumb" question. What named xorg
> version does my package version 1.15 correspond to? X11R7.?

X11r7.7, I think.
http://www.x.org/wiki/Releases/

> Currently, I'm having some bad flicker problems I didn't experience
> previously. I have an old old radeon graphics card and note that the ati
> driver was updated with 6.7. This loads for X before the radeon module.

Sounds similar to the problem that Bill Maltby has been writing about.  
The advice I gave him last:

Boot the last kernel under which you saw "normal" performance.  If 
booting the older kernel doesn't fix the problem, then the problem is 
probably the X11 server.  At that point, I'd start using "yum downgrade" 
to revert individual components, and reboot until you find the change 
that fixes performance.  xorg-x11-server-Xorg and xorg-x11-drv-ati are 
the ones I'd check first.