High CPU load using Fedora?

Before I use linux I heard, it has very good performance on poor hardware. However, I got very high cpu load when using fedora10.

here is the list of my hardware
Memory 512 MB
CPU Intel(R) Pentium(R) M processor 1500MHz

the average rate of my CPU load is 70%, and memory used is 60%.

Optimize:
1. Somebody ask me to disable some service that I don't use.
2. using xfce or even wm instead of gnome,kde
3. remove the damn useless "npviewer.bin"