"nohz=off" and system performance

[Dennis Jacobfeuerborn]

I just noticed that when I boot with "nohz=off" I get improved vmstat 
numbers. When playing a YouTube video I get an idle percentage of around 
25-30 but when I boot with "nohz=off" the system seems to cope much better 
and show an idle percentage of 50. Can anyone shed some light on what is 
going on here?
Given this and the problems described in bug 650934 I'm wondering how 
trustworthy Fedoras system metrics are. Values for load and cpu usage 
shouldn't really be this flaky.

Regards,
   Dennis