ubuntu/kubuntu is sloooooooow!

[Mario Vukelic]

On Tue, 2007-08-14 at 01:23 +0300, metin wrote:
> I can't give specific numbers regarding performance (I did not make any 
> benchmarking) but when you use a system it is immediately evident 
> whether it is fast performing or not.

In any case it is important to know in which way a system underperforms,
otherwise it is impossible to pinpoint the reason. For example, I have
learned that you are interested in desktop performance (responsiveness)
and not server performance (throughput)

>  For example, when you click the 
> k-menu (kde) or gnome-menu it takes up to two seconds for the menu to 
> come up in (k)ubuntu while it is instantaneous in archlinux or pardus. 

I have not seen this on slower machines than yours. I also doubt that
archlinux or pardus add Gnome or KDE performance patches.  Does the
delay only happen the first time you open the menu, when the entries
have to be read from disk? (The menu should then be cached and open
instantly for later accesses).

> This is more or less valid in every desktop operation. I am using all 
> linuxes on the same machine so my system's specs are not relevant.

It really ticks me off when people ask for help, and when I am asking
needed information to diagnose the problem, they tell me I don't need
that. If you are so smart, why do you ask in the first place, go
investigate yourself.

The system specs certainly are relevant. If your system were
bottlenecking on RAM, it would have a different impact on performance
than a slow disk, for example. You DID talk about "older systems" in
your OP, but the one you listed does not fall into that category, IMHO.

The most likely difference in archlinux or pardus (not knowing those
particular distros) is that they mount the disks with the noatime
options. This can speed up disk access a lot. Just add "noatime" to the
mount options in /etc/fstab and remount. 
There was recently a discussion about this on lkml, see here:
http://kerneltrap.org/node/14148

Another possibility (if HD access is really the problem) is that DMA is
not set correctly.