system load

[djsb]

Hi,

I'm having a problem with my system load.
It often goes to values higher than 3 for system load. When i check the top processes and the cpu idle time i can see that the cpu is about 50% idle.

What can influence the system load?

My system information:
- HP P4 2.8Ghz
- 1Gb RAM
- 3 x 80GB harddisk in raid 0
- 16 video inputs all in motion detect


here is a capture of my top:

[root@vigilancia root]# top
09:25:50 up 18:38, 2 users, load average: 2.44, 2.24, 1.84
74 processes: 72 sleeping, 2 running, 0 zombie, 0 stopped
CPU states: cpu user nice system irq softirq iowait idle
total 18.1% 0.0% 9.3% 0.0% 0.0% 0.0% 72.4%
Mem: 1291756k av, 1282128k used, 9628k free, 0k shrd, 329348k buff
552556k active, 571900k inactive
Swap: 2096472k av, 85668k used, 2010804k free 714424k cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND
2786 apache 15 0 62680 59M 60568 S 13.7 4.7 35:55 0 zma
2417 apache 18 0 396 396 332 R 5.5 0.0 0:05 0 rm
2630 apache 15 0 17384 15M 15584 S 2.7 1.2 6:19 0 zma
2617 apache 15 0 128M 118M 117M S 1.9 9.3 12:49 0 zmc
2608 apache 15 0 85976 74M 75420 S 0.9 5.8 6:34 0 zmc
32327 apache 15 0 40524 29M 30420 S 0.5 2.3 1:39 0 zmc
2538 root 16 0 1208 1208 896 R 0.3 0.0 0:00 0 top
1928 mysql 15 0 16840 12M 10768 S 0.1 0.9 57:54 0 mysqld