設定する項目は二つ。
CPUの動作周波数と、動作電圧の制限を緩めます。
$ sudo nano /boot/config.txt
執筆時点では38行目
#uncomment to overclock the arm. 700 MHz is the default. #arm_freq=800
これを
#uncomment to overclock the arm. 700 MHz is the default. arm_freq=1400 over_voltage=5
公式資料によると、手元の機体で設定可能な周波数は1.5GHz。
倍数だと安定するという怪情報も小耳に挟んだので、
CPU/GPU core upper voltage limit. The value should be in the range [-16,8] which equates to the range [0.95V,1.55V] ([0.8,1.4V] on Raspberry Pi 1) with 0.025V steps. In other words, specifying -16 will give 0.95V (0.8V on Raspberry Pi 1) as the maximum CPU/GPU core voltage, and specifying 8 will allow up to 1.55V (1.4V on Raspberry Pi 1). For defaults see table below. Values above 6 are only allowed when force_turbo=1 is specified: this sets the warranty bit if over_voltage_* > 0 is also set.
今回、流石にforce_turboは怖すぎるので5に設定
$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq 1400000
