KDE4 memory usage vs KDE3 => benchmark ?

[cb88]

@energyman composite on indexing off... it feels faster anyway with composite on either way window drawing is laggy I have tried both composite on and off.

It is an ancient i810 video chip though compiz is about all its good at... maybe google earth.

[thyrr]

OK, here are the real world results:

Memory usage before and after the start of:

KDE3:
             total       used       free     shared    buffers     cached
Mem:       3942172     383688    3558484          0       3928     101748
Mem:       3942172     576068    3366104          0      30376     199300

Total: 187MB

KDE4

             total       used       free     shared    buffers     cached
Mem:       3942172     386824    3555348          0       4660     10475
Mem:       3942172    1073012    2869160          0      24796     605136

Total: 670MB

Both environments were run with an empty, new profiles, and four applications which I just ran and kept open:

Akregator, Konsole, Konqueror and Kolorpaint.

Now, don't tell me KDE4 doesn't need a huge optimization.

It's a lot smaller if you exclude the buffers/cache (which you'll get if you read the second line of the "free" command):

383688 - 3928 - 101748 = 278012
576068 - 30376 - 199300 = 346392

Difference: 68380 = 66MB

386824 - 4660 - 10475 = 371689
1073012 - 24796 - 605136 = 443080

Difference: 71391 = 69MB

If you really want to compare memory including cache, run this command to flush the disk cache before logging in:

su -c "echo 1 > /proc/sys/vm/drop_caches"

After logging in, use each app for a few minutes before checking the stats so that it has a chance to reload whatever it actually needs.

Another thing to keep in mind is that if you run KDM 3/4, some of the KDE libraries may already be loaded which will throw off the before/after logging in stats. Either way, it's not like KDE4 is using 400MB more than KDE3.

[energyman]

yeah, you have to reboot between that 'measurements' and empty profile means that nepomuk and strigi is on ...

[birdie]

thyrr

If you had bothered to read my message carefully you would have noticed that I did

echo 3 > /proc/sys/vm/drop_caches

which is far more effective.

And cache memory occupied by any of these environments DOES count, e.g. KDE 4 has a very big icons cache in /var/tmp/$USER-kde4/ which is almost all the time kept in memory by Linux kernel.

[birdie]

Why the heck no one dare make the same measurements and only criticizes me? And I tell you, rebooting is NOT necessary. That's stupid, since Linux allows to clean ALL caches.

[val-gaav]

KDE system monitor tells me that bare naked kde with all other parts of OS takes 350 mb and with the apps you mentioned around 407 mb.

kubuntu 64 bit kwin on, nepomunk off.

[energyman]

val-gaav you too measured crap. Why does nobody read the link I posted?

[val-gaav]

Actually I know it's not accurate ... but AFAIK not accurate means in this case that it's higher then it really is...

I really don't care enough about it to spend time on doing it the right way ... just that the value seems a lot lower then previous "crap" tests imply.

[nanonyme]

If that number includes shared memory, a higher amount could simply mean that the newer version uses more shared libraries (which might be loaded anyhow for different purposes), not that its own memory usage is higher.

[squirrl]

Akondi and etc

Disabling Akondi, Desktop Effects, nepomuk will bring the memory usage down. The odd thing is I use to run KDE on a P2 350MHZ with 128 Megabytes of ram. KDE 3.3?

The real problem is Xorg 7.4 - 7.5 and Linux 2.6.22 - Linux 2.6.31. These things are the ones eating the ram up.

It's as if there were some secret instructions that executed in the older Xorg and Kernel that get turned off in the newer one's. CISC -> RISC.

As a test I took a copy of Slackware 12.1 which ships with I believe the 2.6.24.1 kernel and installed it to a Pentium 1 / 233mmx computer with 64 Megabytes of memory. It was swapping out at the command prompt with no Xorg loaded.

The 2.6 kernel's memory management is a hog. I haven't really read into any modern memeory management algorithms since I read the Dinosaur book. That's probably linux 2.2?

So I can't really be sure if Xorg has much to do with it at all.

Nobody cares about old junk lying around.