Notes for Unraid upgraders. Is your CPU using too much power?

 I upgraded from a Dell T310 to an R720xd.

The X3440 CPU (I upgraded from X3430 to get HT cores) uses an older driver and it doesn't allow idling on my R720xd.

In the terminal:

cat /sys/devices/system/cpu/cpufreq/policy0/scaling_driver

gives and output of "acpi-cpufreq" which is incorrect for the 2697v2 Xeon I have for example. 

"Sandy Bridge and newer use the intel_pstate driver"

So, to fix.