"top" shows different CPU usage than "ps faux"

[redhatter]

Hi,

I just noticed that "top" shows a CPU usage percentage markedly 
different than "ps faux" for example.

In this case, a java process running at 433% in "ps faux" is shown as 
runnging at 661.4% in "top"

Both programs get their data from the /proc filesystem I imagine, so 
there could be a summation bug in either of them.

Or is there some rational explanation?

Best reagrds,

-- David