32 bit faster than 64 bit

I ran a DAQ program on LabVIEW 2011 32 bit and it used 5-6% CPU according to the Task Manager.

I ran the same program under LabVIEW 2013 64 bit and it used 8-9% CPU according to the Task Manager.

I thought the 64 bit version would be more CPU effecient than the 32 bit version.  What's up?

Thanks,

Mark