In Task Manager, in the Details tab, the System Idle Process CPU time seems broken. Two problems:
1. It doesn't start counting from zero until Task Manager is opened. All other processes start counting from zero at system startup time. Also System Idle Process did correctly start from zero at startup in Server 2008 R2.
2. It stops dead at zero CPU usage after approximately 7 minutes of CPU time (7:09 on a Hyper-V host with 8 processors, 7:08 on a VM with 8 virtaul processors). So it stops in under a minute with 8 processors.
The System Idle Process CPU usage and total CPU time are useful metrics to understand average CPU load on the system. They worked in Server 2008 R2, and seem broken in Server 2012 RC.
