Comment 26 for bug 177895

Enabling multi core power savings could help:

echo 1 > /sys/devices/system/cpu/sched_mc_power_savings

This minimize the number of cores being loaded and hopefully enable idle cores to drop into lower power states. However my
tests show that the savings may be marginal.

The sched_mc_power_savings setting depends on the CONFIG_SCHED_MC being enabled. Currently only the x86_64 kernels have this as default.