Hi!
Some of you may have already encourtered the following problem :
on my SunBlade 2000 and SunUltra 60 workstations, equiped with
20" CRT displays, I experience sporadic vibrations of the whole
image on the screen. The vibrations consist in horizontal
deviations of the odd lines relatively to the even lines.
For examples, and 6 x 6 pixel area of the screen that should
look like :
aaaaaa
bbbbbb
aaaaaa
bbbbbb
aaaaaa
bbbbbb
(where "a" represents a pixel on an odd screen line and "b"
an pixel on an even one)
rapidly (with a > 10 Hz frequency) varies between :
aaaaaa
bbbbbb
aaaaaa
bbbbbb
aaaaaa
bbbbbb
and
aaaaaa
bbbbbb
aaaaaa
bbbbbb
aaaaaa
bbbbbb
I would like to insist on the fact that this problem happens
on the whole screen at a time (the 6x6 example was just to save space
on this message).
By trial and error, I discovered that I could reproduce this
flickering by writing a simple program that allocates chuncks
of memory of a fixed size. An implementation in pseudo-C would be :
while (1)
malloc(1000 * sizeof(float));
When I launch that program, the flickering really prevents
anyone from working on the machine, as the amplitude of the
horizontal bias from the two extreme positions shown above
nearly reaches 1 millimeter.
I have launched my program on several Sun Ultra 60 stations,
and this problem is perfectly reproductible.
So, I would like to know if some of you have already been
through this, and if you found an explanation. Sun would
not admit that it's a bug of their motherboards. But I would
think it is.
Thank you for your answers !
Jery P.