新版rpi4b板子为SoC电压配备了独立开关电源的（图中圆圈处），将在Bullseye系统更新后从1.5Ghz自动提频至1.8Ghz 。老外你逼我出手了！

网页https://www.raspberrypi.com/news/bullseye-bonus-1-8ghz-raspberry-pi-4/

1.5GHz to 1.8GHz

But some of you may have noticed another upgrade. Users with recent Raspberry Pi 4 devices will find that their default turbo-mode clock has increased from 1.5GHz to the 1.8GHz used on Raspberry Pi 400. “Recent” in this case means any 8GB Raspberry Pi 4, or a 2GB or 4GB board with the extra components circled in the image below. This is the dedicated switch-mode power supply (“switcher”) for the SoC core voltage rail, and was introduced when we shuffled the allocation of switchers to rails to support 8GB.

Through extensive testing on the production line, we have qualified an operating voltage for 1.8GHz, and satisfied ourselves that the new switcher is able to supply enough current to run even the heaviest workloads at that speed.

Overclocking older Raspberry Pi devices

What about older devices? Even the launch-variant Raspberry Pi 4 has gained a reputation for overclockability, and most units will run most workloads at well over 1.5GHz with a little extra core voltage. The latest firmware (included in the Bullseye image) will even do its best to figure out the best voltage to apply for a given overclock. To manually replicate the new operating point on an older board, just add the following line to your config.txt file: