Overclocking Arduino UNO with liquid nitrogen
That seems to be the case with a modder called Michail who has managed to overclock an Arduino using liquid nitrogen, no less. Cooling to -196°C he hits speeds of 65.3MHz.
Why overclock a dev board with liquid nitrogen? He answers this one in a blog post – because he could, and he wanted to learn how electronics behave at cryogenic temperatures. And he says he was just curious to see “how much juice you can squeeze out of AVR if you push hard enough”. (AVR is the “C” environment for programming Atmel chips.)
And why an (ATmega328P-based) Arduino UNO when there are many faster microcontrollers? Because of the popularity of Arduino among geeks and amateurs, he writes. For practical applications it is easier and cheaper to just use Cortex-M3/M4 based microcontrollers or FPGA (and I had these devboards too).
As BarsMOnster he writes on YouTube:
“Arduino overclocking with Liquid Nitrogen cooling (-196°C). Maximum stable frequency is 65.3Mhz at 7.5-8V supply voltage. Higher or lower voltages are unstable at this clock. Stability was tested by my custom stress test for more than 1 hour. During this overclocking test 3 litres of Liquid Nitrogen were consumed. At frequencies higher than 65.3Mhz it was failing at SRAM read/write test.
There were a number of hardware issues with Arduino at cryogenic temperatures: capacitors loose most of their capacitance, brown-out detection was tripping, 3.3V linear regulator for LCD backlight supply was failing. They were solved by soldering capacitors which don’t loose too much capacitance (NP0 and X7R dielectric materials), disabling brown-out detection and bypassing 3.3V linear regulator. Also, yellow LED became green (due to wider bandgap at lower temperature) and then stopped working at all – apparently there was insufficient voltage to light it.
For comparison, at 5V supply and room temperature maximum stable frequency is 32.5Mhz, at 8V – only 37Mhz.”