With no calls the CPU there is no high CPU, when we start calling the CPU gets up.
Now the CPU for the asterisk process is 280%, whilest the load is very low at 0.04.
top - 14:13:50 up 1:48, 4 users, load average: 0.04, 0.20, 0.30
Tasks: 212 total, 1 running, 210 sleeping, 0 stopped, 1 zombie
Cpu0 : 26.3%us, 35.2%sy, 0.0%ni, 38.1%id, 0.0%wa, 0.0%hi, 0.4%si, 0.0%st
Cpu1 : 31.4%us, 34.1%sy, 0.0%ni, 34.1%id, 0.0%wa, 0.0%hi, 0.4%si, 0.0%st
Cpu2 : 28.6%us, 32.8%sy, 0.0%ni, 38.2%id, 0.0%wa, 0.0%hi, 0.4%si, 0.0%st
Cpu3 : 30.4%us, 30.8%sy, 0.0%ni, 38.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 8051600k total, 734436k used, 7317164k free, 19928k buffers
Swap: 1738748k total, 0k used, 1738748k free, 124540k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
6511 root 20 0 2793m 170m 13m S 280.4 2.2 19:44.20 asterisk