[Unit]
Description=Hold the CPU at full clock (the face costs about half the CPU at 1.8 GHz as under ondemand)

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c 'for g in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo performance > "$g"; done'

[Install]
WantedBy=multi-user.target