system monitor, dual cpu % during emerge-webrsync

[hobo2]

I have gnome system monitor running on desktop and while running emerge-webrsync (I am behind a corporate proxy so must use it to update), the dual cpu % is shown as 100% for cpu1 and cpu2 is barely 2 or 3 percent (that's two or three percent) - why is this not distributed evenly across both cpu's?

[LoDown]

This is just a guess, but I would say it is because emerge-webrsync is a single thread process, thus only uses one processor. Maybe someone more familiar with that program can comment?