Laptop nc8430, 4GB Ram and fglrx

[jens]

On my laptop nc8430 with 4GB Ram, when using fglrx driver gnome becomes extremely slow. With 2 GB Ram everything is fine. Workaround is kernel-parameter mem=3G

[Jörn Dreyer (j.dreyer)]

Same here. 32Bit Ubuntu desktop. Also tried server before I found out desktop now has HIGHMEM4G set. The BIOS only reports ~3.3G of ram. Linux reports 3374736kB of RAM. Using vesa I can work with X just fine. As soon as I start X with fglrx the system becomes horribly slow. mem=3G will be my workaround too.

[Jörn Dreyer (j.dreyer)]

uname -a: Linux teacup 2.6.22-12-generic #1 SMP Sun Sep 23 18:11:30 GMT 2007 i686 GNU/Linux

[udude (igal)]

me too (on 7.10)...

$ uname -a
Linux svyfleishmanlnx 2.6.22-14-generic #1 SMP Sun Oct 14 23:05:12 GMT 2007 i686 GNU/Linux

Jörn - I'm kind of a newby. May I ask how did you verify that the destop kernels have HIGHMEM4G set?
also - does setting HIGHMEM4G mean that they I _should_ be able to see 4G (/proc/meminfo) when not using fglrx?

[Jörn Dreyer (j.dreyer)]

> May I ask how did you verify that the destop kernels have HIGHMEM4G set?
/boot should contain all configs for the kernels installed on your system:
$ grep _HIGHMEM /boot/config-2.6.22-14-generic
# CONFIG_DEBUG_HIGHMEM is not set
CONFIG_HIGHMEM=y
CONFIG_HIGHMEM4G=y
# CONFIG_HIGHMEM64G is not set

> does setting HIGHMEM4G mean that they I _should_ be able to see 4G (/proc/meminfo) when not using fglrx?
this one is more complicated.
short answer: it depends on your cpu, mainboard, bios, os and PAE support - on 32bit laptops most likely not.
long answer: http://blogs.msdn.com/dcook/archive/2007/03/25/who-ate-my-memory.aspx

concerning this bug: I somewhere read it had to do with MTRRs. However, my problem is ... deferred as I will simply use 3GP of physical memory ... my mainboard or bios does not seem to support PAE.

[Mika Fischer (zoop)]

I have a smilar problem on a Santa Rosa laptop with Intel X3100 graphics. GDM takes ages to load. And there were warnings concening MTRRs...

I think this is a serious bug, since upgrades to 4GB will become much more common now...

I'll try to get the complete error message soon...

[Andy Whitcroft (apw)]

This is not a bug in the linux-meta package, moving to the linux package.

[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.