Sharing processor in LPARs

We recently added a second partition at V5R3 and I was under the impression 
that "dynamically" moving partition processor power meant that the operating 
system would be smart enough to do it on its own when it sensed that one 
partition was under utilizing its CPU share and another partition was CPU 
constrained.  Upon reading up on this though, it looks as if dynamic means 
without restarting partitions.  Can someone confirm this?

Thanks,

Bryan Burns
ECHO, Inc.