Workaround to for 177.80 Gnome Terminal Corruption.Tested!

[taltalon]

Guys,
nvidia 177.80 on ubuntu 8.04 works very nice, the problem for me on my Dell D630 with Quadron NVS 135 is that gnome-terminal sessions are corrupted - missing lines, or you need to do ctrl-L to redraw the screen.

I found some clues in this forums that this is related to the powermizer throtteling down to the lowest performance settings and its seems correct. After much research i found away to force the nvidia driver to LOCK to the full performance mode of the GPU and not to throttle back.

Some Myths:
any changes you made in xorg.conf regarding RegistryDwords and the PowerMizer settings SIMPLY DO NOT WORK.

How to REALLY make it work:
To make it work we must tell the nvidia kernel module to set some RegistryDwords. For some reasone this settings is being ignored from the xorg.conf and the driver.

on ubutu: go to /etc/modprobe.d
1. backup nvidia-kernel-nkc to somewhere else - not the same directory.
2. edit the file and add another line at the end:

options nvidia NVreg_Mobile=1 NVreg_RegistryDwords="PerfLevelSrc=0x2222"

i use the the original nvidia driver from nvidia site. thus the kernel module name is nvidia , not nvidia_new or nv or what ever. just nvidia.

Note the NVreg_Mobile=1 - without this settings the rest of the line will *NOT* work. this tells nvidia module that the device to be used is a laptop.

PerfLevelSrc tells the nvidia drive to lock its powermizer to the top performance.
for me it locks the GPU clock to 400Mhz and memory to 594mhz.

Save. Reboot. Enjoy.
You can double check in Nvidia X Server Settings GUI that it stays locked.

Have Fun,
Taltalon.

[jcornwall]

http://www.nvnews.net/vbulletin/show...hp?t=120829#13

A more reliable, albeit incomplete fix. Tweaking the GPU clock just alters the chance of this race condition happening. Aaron's Compiz patch still has a race condition but eliminated the problem on my system.

[taltalon]

Intersting,
but since i "disabled"/lock powermizer - i never get any corruption in any terminal app.
works flawlessly.

further more you get by far better performance from compiz. perviously when i rotated the desktop in 3d to the next virtual screen the rotation was kinda slow but then it picks up speed. i guess this is because it takes time to the powermizer to understand i want full performance.

which wrapper file am i suppose to edit as mention in the link you send?
thanks

[Kirurgs]

Actually that Mobile thing is not required! I have tested this myself and it works flawlessy! So I don't really know what this mobile thing actually does!
However, I end up using lighter gtk theme and I think it's useable and since PMiz is not at full throttle all the time - energy efficient too

What is interesting however, is that using this trick makes my GPU to heat up to 55-57 degrees, without that it's 53-55, which is not that big difference at all...

About the terminal thing, I have blank terminal only when I maximize it and unmaximize - blank, then enter at terminal window and it gets displayed again...
No that big problem, really...

[jcornwall]

Originally Posted by taltalon

which wrapper file am i suppose to edit as mention in the link you send?
thanks

You just need to add Aaron's repository to /etc/apt/sources.list, then do a software update to receive patched Compiz packages.

deb http://ppa.launchpad.net/aplattner/ubuntu hardy main
deb-src http://ppa.launchpad.net/aplattner/ubuntu hardy main

(You can also do this in the Synaptic Package Manager GUI.)

I think you'll find it fixes the terminal corruption bugs without forcing the card to maximum power. Accepted that Compiz performance will still be poor at low performance levels, though.