[R] WinXP exhibits sluggish graphics window movement & mouse tracking (repainting?) over windows graphics devices

[Richard Yeh]

I just noticed when using 2.6.1, 2.6.2 (2008-02-08), 2.6.2pat
(2008-02-21 r44582), and 2.6.2pat (2008-03-24 r44975) on my poor old
Celeron D330 (2.6 GHz; 3.5 years old) running Windows XP, that the
mouse cursor appears to be redrawn more sluggishly when the pointer is
over R windows graphics devices than over the R console window or
other applications' windows. The slowdown seems to start only after I
plotting something in the window (running "windows()" to open the
device does not cause any slowdown), but the behavior starts after a
"plot(rnorm(100))". The slowdown seems to depend on the area of the R
graphics window that is visible. The slowdown also occurs when moving
the plot window.  For example, if the graphics window is frontmost,
and I want to move it until it is mostly offscreen, then the movement
is jerky.  However, once the window is mostly offscreen, dragging it
back onto the screen is smooth and fast.  (When I drag windows, I only
see the frame, not the contents.) This seems to affect SDI and MDI
modes.  The Windows task manager confirms that when the plot window is
frontmost, Rgui.exe takes most of the CPU time.

My graphics card is based on an ATI Radeon 7000, with 32 MB of RAM.

I am surprised that I never noticed this before. Nobody else seems to
have reported it to the r-help list. Is this problem restricted to my
system? (My work machine is much newer, and I do not notice the
problem there.)

-- 
607-351-4838 / Richard.C.Yeh at gmail.com