Overclocking Raspberry Pi Pico 2
How fast can RP2350 really go? Mike starts his Christmas holidays with a deep dive into Pico 2 overclocking, with the assistance of a seasonally appropriate amount of dry ice ❄️
A couple of years ago Raspberry Pi posted about overclocking a regular Pico to a ridiculous degree - achieving a 1 GHz overclock and (briefly) boosting the performance of the Pico above the original Pi.
Picos overclock very well, and the original Raspberry Pi Pico will normally run at over 400MHz if given a 1.3V core voltage. On the RP2040 that is as far as you can easily go because the on-board voltage regulator is limited to supplying a maximum of 1.3V.
When I first got my hands on the RP2350 datasheet, one thing I noticed rather quickly was that the voltage regulator could have the voltage limit disabled, so that voltages above 1.3V could be requested. And once I got a Pico 2, I was intrigued to see how it would behave at higher core voltage (and whether the magic smoke would come out if I raised the voltage too high!)
Initial experiments
Using this MicroPython script I was able to request different voltages from the regulator. To find out how fast the RP2350 would clock at a given voltage I ran a simple test that computed 100 factorial and checked the answer was correct, and then incremented the clock speed and continued until it stopped working.
I then did a more rigorous test using the MicroPython performance benchmark to find out whether things were stable. Generally I had to back off the CPU clock by 20MHz or so in order for the performance benchmark to run multiple times cleanly, compared to how fast it would pass the very simple 100! test. I live bleated (that's what we're calling Bluesky posts for now) my experimentation and some details about the RP2350 as I was doing this.
Voltage, max stable clock speed and temperature for those initial tests was as follows:
Voltage Max Clock Temperature 1.1 V 312 MHz 25.6 C 1.3 V 420 MHz 33.6 C 1.5 V 512 MHz 44.4 C 1.7 V 570 MHz 53.7 C
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