Help: Mouse cursor lags badly

Paul A. Rubin rubin "at"
Fri, 18 Dec 1998 10:43:42 +0000


I'm testing VNC (Windows client, Linux server) with a simulator we run.
The simulator paints a rather large (1280x1024) but simple initial screen,
dominated by a grid with a small number of boxes and circles, with some
buttons on the right.  That takes a few seconds on the PC client, which is
acceptable.  Once the initial screen is drawn, the mouse cursor updates
essentially instantly until I start the simulator.  While running, the
simulator moves a few very small and plain sprites around the screen, and
updates a clock in one corner.  The sprites are simply circles with "tails"
indicating direction of movement and a few identifying characters each.
The screen updates at approximately one second intervals.  There's no
perceptible difference in the update speed using VNC v. using the Linux
console, *except* that once the simulator is running the mouse cursor takes
several seconds to catch up to its local counterpart (and mouse clicks take
a long time to register).  This is a big problem, as part of the simulation
involves the operator left- or right-clicking on one of those moving sprites.

Any suggestions on what I can do to tune performance?  I think I've tried
every compression alternative, and I tried running the server with -t 1 and
-t 40 (whatever that accomplishes -- I'm not a Unix/Linux user, so I'm just
taking random potshots here).

Thanks in advance.

-- Paul Rubin

* Paul A. Rubin                                  Phone:  (517) 432-3509     *
* Department of Management                       Fax:    (517) 432-1111     *
* The Eli Broad Graduate School of Management    E-mail: rubin "at"      *
* Michigan State University             *
* East Lansing, MI  48824-1122  (USA)                                       *
Mathematicians are like Frenchmen:  whenever you say something to them,
they translate it into their own language, and at once it is something
entirely different.                                    J. W. v. GOETHE

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