Some issues with waiting time

[ARP]

Hi,

I have been using litespeed webserver for a few months now and I'm quite happy with how this arrangement is working. I have some small issues though. Some of the sites I host, mostly Joomla, Presta Shop and Magento, have a very high wait time when they're accessed, but just a part of the above mentioned CMSes. At first, I suspected that the server is slow, but this issue keeps popping up when the load is 2-3. the server is a quad-core xeon, 8 Gb DDR3, Raid 10, SATA, Centos+cPanel and the databases are hosted on a remote mysql server which is also a quad-core xeon, 16 Gb DDR3, RAID10 and SAS drives with a gigabit connection between the two servers.

Top looks something like this:

top - 22:26:32 up 73 days, 22:01, 3 users, load average: 2.55, 2.46, 2.63
Tasks: 194 total, 2 running, 192 sleeping, 0 stopped, 0 zombie
Cpu(s): 17.7%us, 5.1%sy, 0.2%ni, 75.1%id, 1.1%wa, 0.0%hi, 0.5%si, 0.3%st
Mem: 7340032k total, 6995764k used, 344268k free, 232276k buffers
Swap: 4194296k total, 1092k used, 4193204k free, 5067512k cached

I've also attached a screenshot with the load time of one of the sites. The servers are located in europe so accessing from amsterdam shouldn't take that long.