Fedora-10 nightmare update2

[Arne Chr. Jorgensen]

hi,

I did describe noise/glitches on the screen.  


I will try to describe it a little bit:  
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It is like an old CRT with a weak
high voltage supply - the screen may shrink or expand. And there are noise
streaks across the screen.

As this is a laptop with LCD, it has to do with updating of the screen. Loading is typical if you open a folder on the screen, and it will update/paint to the screen. In such cases the shrinking/expansion may be
20-40 mm for a brief half second or so. Sometimes leaving a horizontal band
for in the middle.  

                              
The reason:
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The "new" cpu scaling can not keep up. I have it set to "on-demand".
 800MHz - worst, as described above.
1600MHz - very improved, the shrinking/expanding is only 5-10 mm 
1800MHz - the effect seem gone.
2000MHz - have not seen any noise/glitches.


Discussion:
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Watching the System Monitor, the graphs are smooth, the loading on CPU1 and
CPU2 seem nice compared to earlier kernels with abrupt switching from one
to the other. 

The "new" scaling algorithm have at dropped CPU temperature with more then
10 degree centigrade. For a couple of years of running Linux, you could not
keep your hand against the underside of the machine for any long time. And
you would burn yourself if holding your hand close to the ventilation port.

I have never checked with AMD what cores temperatures would be reasonable,
but above 70 centigrade was not uncommon. As I write, the CPU is running
at 800MHz and the CPU temp is 55 centigrade.  

I would rather live with some noise/glitches on the screen and keep the temperature down. 

For a couple of years, I have almost never been running without power attached, as you run out of battery power within an hour ?? ( have no good
figure on this )

The computer behaves somewhat closer to how it is running Microsoft Vista,
yet I have never seen glitches and noise there. But the lesser loading,
the fan speed and temperature is much more close to each other. 

To remove noise on the screen, perhaps a sharper controller term could be
used, at the cost of the more smooth behaviour it has now. Perhaps the
refresh of the screen could be held off/protected during scheduling. I don't know. 

Knowing some reasons for this and if need be, just enable a higher prosessor speed, works for me.

//ARNE