The Raspberry Pi RP2040 Gets a Surprise Speed Boost, Unlocks an Official 200MHz Mode
Spec sheet change brings a faster clockspeed than the 150MHz RP2350 — though both can, in many cases, run even faster out-of-spec.
Raspberry Pi has released a new version of its pico-sdk software development kit for the RP2040 and RP2350 microcontroller families — and it comes with a speed boost for the RP2040, bumping its maximum rated clock speed to 200MHz.
"RP2040 has now been certified to run at a system clock of 200MHz when using a regulator voltage of at least 1.15 volts," explains Raspberry Pi's Graham Sanderson of the performance bump in the latest SDK release. "With this version of the SDK, you can now select a 200MHz clock for RP2040 simply by setting SYS_CLK_MHZ=200 via preprocessor define. The regulator voltage will automatically be raised for you if necessary."
The Raspberry Pi RP2040 launched in January 2021 as the company's first in-house microcontroller chip — though not its first in-house chip design, which would arrive aboard the Raspberry Pi 5 as the RP1 "southbridge" chip — aboard the Raspberry Pi Pico with a 125MHz stock clock speed. As with the majority of silicon chips, though, that was never a hard limit, and tinkerers have overclocked the part considerably — always with the understanding that it would be operating out of spec.
Now, that 125MHz limit has been lifted to an impressive 200MHz — boosting performance without having to run outside officially-sanctioned limits. In doing so, the RP2040 runs at a faster clock speed than the later RP2350 family — though the latter is based on the more powerful Arm Cortex-M33 core, alongside open-silicon Hazard3 RISC-V cores, which will still offer better performance for common workloads than the RP2040's Cortex-M0+ cores running at a faster clock speed.
Those wondering about that clockspeed disparity between the old and new controllers can take heart in Sanderson's carefully-worded hint: "We may certify new frequencies for the different platforms in the future," he writes, leaving the door open for a similar speed boost for the RP2350 family too.
More details are available in the pico-sdk release notes. The new clockspeed won't be enabled by default, Sanderson has confirmed, owing to concerns of backwards-compatibility with existing programs; those looking to enable it should set PICO_USE_FASTEST_SUPPORTED_CLOCK=1 in CMake or as a preprocessor definition, which will be forwards-compatible with other clockspeed boosts for any supported chips.