Hints for using Intel GMA500 with Karmic?

[Marcelo Magno T. Sales]

Hello,

I have a Sony Vaio P688 netbook, which uses the Intel GMA500 video 
chipset.
I have followed the instructions at 
https://wiki.ubuntu.com/HardwareSupportComponentsVideoCardsPoulsbo and 
now I have much better video support than that provided by a standard 
Karmic beta installation.
However, after reading that page and some posts at forums.ubuntu.com, 
I'm under the impression that it is possible to achieve yet better 
results.

I'm getting only about 9 fps when I execute glblur -fps -window and the 
article says 14 fps is considered very slow for this driver/chipset. 
However, I have tried to add "mem=2000mb" (and other smaller values too) 
to /etc/default/grub and nothing has changed in 3D performance. Of 
course, I have executed update-grub and rebooted after each try.

2D performance is relatively fast, but when I activate composition and 
desktop effects in KDE (using XRender, openGL does not work at all), 
everything is choppy and slow. Also, suspending does not turn off the 
video (with or without composition enabled). With the default driver 
supplied with Karmic, suspend and wake up were working ok.

Someone with another VAIO P series has reported at the forums that the 
special keys for adjusting LCD brightness do work for him, but here they 
do not (but I can adjust it using the battery monitor plasmoid, so this 
is not a big problem).

And last, the sound always works good right after I login and for a few 
minutes more, but then it stops and does not work again until 
I reboot. Is there anything I can do about this? Sometimes error 
messages like "hda-intel: spurious response" are logged, but I could not 
find anything useful about this.

Thanks,

Marcelo