[horde] pb with load of apache

[Service Informatique IF]

Hi,

Sorry for my English but I will try to explain you the problem i have.

My server which serve only Horde5 for 50users max (KVM : 4procs bi-core, 
4Go ram) - and mysql is on another server, has a load average of 3-4 and 
only with apache processes.(ubuntu 12)
I think I have max 20 users simultaneously
FYI, mysql server load is 0.3 so I think it's not a pb from the mysql 
server.

For reading or writing mails, it's not a problem, but for using 
kronolith, we have to wait 10-20s to save a new event or modify one.

And with lightning by caldav, 50s to synchronise a calendar with 30 
events (one is recurrent weekly)

I follow this page :
http://www.horde.org/apps/horde/docs/PERFORMANCE
but nothing better

And I have nothing in Horde log.

Thanks in advance for your help.