I have done a fresh wordpress install on a new database. This is what I have got a result of:
top - 10:45:49 up 20:29, 3 users, load average: 13.04, 7.88, 3.62
Tasks: 109 total, 11 running, 98 sleeping, 0 stopped, 0 zombie
Cpu(s): 91.0%us, 4.5%sy, 0.0%ni, 3.7%id, 0.0%wa, 0.0%hi, 0.8%si, 0.0%st
Mem: 3990672k total, 1048072k used, 2942600k free, 14100k buffers
Swap: 5804028k total, 34040k used, 5769988k free, 125204k cached
It now seems to be using less memory, but the same CPU