Kernel parameters that affect the X Window System
Although the following kernel parameters do not directly affect
performance, they are important for the correct operation of the
X Window System,
the Desktop, and
You may be unable to start an X client if you do not enough of
these resources configured.
``Configuring kernel parameters''
for details of how to change the value of kernel parameters.
For more information about tuning STREAMS resources, see
Set the value of this parameter to 0 to allow the process table to grow
Limits the number of processes that the system will run on behalf of a user.
Each window requires at least one process. Note that local
applications running in a window may start several additional processes.
Specifies the maximum number of files that a process
(including the X server) can have open simultaneously.
This limits the number of X clients that can be started
because the X server opens a file descriptor to each client.
In addition, the X server requires about 10 file descriptors
in order to read fonts, color maps, and so on.
Allow at least as many pseudo terminals as the number of windows that
will be opened for use on the console, by X
terminals, and X clients. If necessary, you can change
the number of pseudo terminals configured for use using the
mkdev ptty command.
Allow at least four stream heads for the
X server plus four for each
NSTREAM should be approximately
four times the value of NSPTTYS.
This parameter controls the maximum number of 4KB pages of memory
that can be dynamically allocated for use by STREAMS messages.
Allow at least 125 pages plus 125 pages for each X
terminal that is supported.
Two stream pipes are needed for the X server plus
two for each local X client.
NUMSP should be approximately
twice the value of NSPTTYS.
Case study: memory-bound workstation
Tuning X server performance
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003