In a nutshell: For many, modern high-end overclocking is arguably more about the sport of it than gaining much of a sustained performance edge. These days, throwing obscene amounts of voltage at exotic-cooled hardware is how the big boys play and is almost always a recipe for success – key word, “almost.”
Pieter-Jan Plaisier, better known in overclocking circles as SkatterBencher, recently attempted to set a new world record clock speed on a Raspberry Pi 5 using tried and true tactics from the PC space combined with a couple of platform-specific tricks. Despite weeks of trial and error, the Pi 5 hobby board proved mostly unreceptive.
At the heart of the Raspberry Pi 5 is a Broadcom BCM2712, a 64-bit quad core Arm Cortex-A76 CPU that operates at 2.4 GHz out of the box. Using a slightly beefier air cooler, SkatterBencher was able to push the chip to 3.0 GHz without too much effort.
In preparation of the world record attempt, the OCer switched to the official Raspberry Pi 5 operating system and applied the NUMA (non-uniform memory access) patch. A liquid nitrogen pot designed for small chipsets proved to be just the right size for the Pi 5 platform, yet even after beefing up the power circuitry and swapping out the crystal oscillator, results were poor.
Ultimately, SkatterBencher was only able to achieve a clock speed of 3.4 GHz for benchmarks and a maximum configurable speed of 3.6 GHz. Anything beyond 3.6 GHz resulted in the system locking up. In short, the setup simply lacked the sort of temperature and voltage scaling that is typically attainable on other platforms.
The experiment was not a total loss, however, as SkatterBencher said he learned a lot about Linux and got to perform some advanced hardware modifications. Still, it is a bit disappointing that the Pi 5 came up short in terms of temperature and voltage scaling. Worse yet, figuring out why that is the case will be extremely difficult without the proper development tools.