[Texmacs-dev] TeXmacs performance and graphics card drivers

[Felix Breuer]

Hello everyone!

If you are running TeXmacs on Linux with an ATI graphics card using
ATI's proprietary "fglrx" driver switching to the open source "radeon"
or "ati" drivers, or running the new Xgl X Server [1] might give you a
significant boost in performance.


Long Story: About a year ago I bought a new system with an ATI graphics
card. When I needed to use TeXmacs again, I noticed that it had become
much slower (when scrolling and editing) then I was used to. I did not
investigate the cause of this, I supposed TeXmacs was to blame. However,
these days I tried out the new Xgl X Server [1] which is an X
implementation on top of OpenGL. And all of a sudden TeXmacs performed
significantly better. So I investigated further and found that the open
source ATI drivers also provide a better performance in TeXmacs then the
"fglrx" drivers using a standard X server.

Bottomline: The "fglrx" driver has a poor 2D performance that affects
TeXmacs significantly. You can work around this by either having Xgl
perform the X drawing operations using the 3D API of the driver or
switch to an open source X driver that has a better 2D performance.

I would be interested if others can observe the same phenomenon. I could
observe this under several Linux distributions using several versions of
the fglrx driver. Also, do nVidia's proprietary drivers do a better job?


The fact that current graphics cards are optimized for 3D operations and
ATI at least does not seem to care for a decent 2D performance suggests
that an OpenGL rendering backend for TeXmacs might really be worth the
effort. Of course, time is short and this is a big piece of work, so we
cannot expect this to happen anytime soon. In the meantime, I hope the
above helps.


Regards,
Felix