I recently upgraded KDE from version 4.4 to 4.7 Now I experience huge difficulties with system performance.

Akonadi_agent_launcher (with paarent process akonadi_control) claim 85% of of my 2GB memory. At the same time the system disk is constanly active for 10-15 minutes. During this this time my system hardly respond and is in orictice useless.

Does anyone have the same problem? Any cure?

I use a Phenom II x6 processor and a Linux 2.6.39-gentoo-r2 kernel.
SATA 6GB/s ports to a regular HD

My KDE version is: 4.7.4

to determine app using your disk (as it might be Nepomuk) run iotop (probably need to install it) or add io read and io write colums in Ksysguard and sort descending. If Nepomuk try disabling Nupomuk desktop search in systemsettings

restarting KDE did not help?

why 4.7 and not 4.8 - not available?

I added io read and io write colums in Ksysguard and sortet descending. No application show io activity. But akonadi_agent_launcher konsumes 1.7 GB of my 2 GB RAM. It is during this time, 10 - 15 minutes the disk i sactive contantly. My system is useless during this period. After 10- 15 minutes akonadi_agent_launcher gives the memory back. After that I can start use my system more normally.

It does not help to disbale "Display events" in the digial clock settings menu (under Calendar). It does not help either to deactivate Neopmuk altogether in in System settings. After restard of KDE the same problem persist.

did you check you swap, is Akonadi ram usage forcing swapping? the command free should show if swap is being used

did you previously use Kontact or any of the KdePim apps? If you use Kmail2 then you Akonadi is a requirement (as best I can tell)

You could try removing all Akonadi files, something might have been corrupted, at restart of KDE they should be regenerated to the defaults but you will loose any meta data added.
~/.config/akonadi/
~/.local/share/akonadi
~/.kde4/share/config/akonadi*

I've moved this to

Kontact & PIM Queries related to Akonadi, KMail, Kontact, KAddressBook and other KDE PIM applications are welcome here.

Maybe mention Akonadi ram usage in subject title

You could try and change your swappiness settings - I only have the arch wiki link but am sure you'll find something applicable to gentoo as well https://wiki.archlinux.org/index.php/Sw ... nce_Tuning

I checked the swap usage with free. I have 3 GB of swap sace. Typically 10% - 20% of it is used constantly whether the disk is working frantically or not. Some times there are peaks up to 1.5 GB.

If you have 2gb or more RAM, try disabling swap prior to logging in.