[hpham]

well... from the top command, when there are 13+ tasks running, the load still going up to 12+. There is still nearly 2GB free RAM.

top - 00:31:35 up 15 days, 14:26, 1 user, load average: 13.24, 8.43, 9.18
Tasks: 127 total, 13 running, 114 sleeping, 0 stopped, 0 zombie
Cpu(s): 43.6%us, 4.0%sy, 0.0%ni, 0.7%id, 0.0%wa, 0.1%hi, 0.2%si, 51.5%st
Mem: 4194304k total, 2531036k used, 1663268k free, 225356k buffers
Swap: 2097144k total, 0k used, 2097144k free, 1825460k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23648 mysql 15 0 358m 82m 4876 S 42 2.0 49:46.34 mysqld
6510 user-name 17 0 99280 31m 21m S 28 0.8 0:21.27 lsphp5
6608 user-name 16 0 98.0m 32m 21m R 24 0.8 0:23.17 lsphp5
4877 user-name 16 0 98.2m 32m 21m R 20 0.8 0:24.97 lsphp5
7570 user-name 16 0 98.0m 32m 21m S 20 0.8 0:03.42 lsphp5
7522 user-name 19 0 99488 31m 21m R 19 0.8 0:02.24 lsphp5
3560 user-name 15 0 100m 32m 22m R 15 0.8 0:32.80 lsphp5
7314 user-name 17 0 98.2m 32m 21m S 9 0.8 0:05.31 lsphp5
4981 user-name 18 0 99492 31m 21m R 5 0.8 0:29.18 lsphp5
5529 user-name 18 0 98.2m 32m 21m R 5 0.8 0:27.71 lsphp5

Any other tip please? I am using lsws 2-CPU license on quad-core CPU server
Thanks.