3600 MHz Raspberry Pi 5 with Liquid Nitrogen

https://skatterbencher.com/2024/11/11/3600-mhz-raspberry-pi-5-with-liquid-nitrogen/

by jonatron • 2 years ago

201 74 2 years ago

skatterbencher.com

jdenning8• 2 years ago

I won a science fair when I was a kid doing this with a 286; it worked great except for all of the condensation :D

ant6n• 2 years ago

A 3600 MHz 286?! Clearly you jest.

redundantly3• 2 years ago

Yo, Imma need you to provide more details, this sounds super awesome! Do you perhaps have any pictures or the original paper for your project?

jdenning8• 2 years ago

It really wasn’t that fancy, I didn’t even measure the clock speed - just wrote a little program (I think it was in QBasic) that calculated factorials or something (don’t remember the details), then measured performance difference between no cooling, ice water, and liquid nitrogen. Made some graphs, printed with my color inkjet (very fancy at the time).

It was more a situation of being a computer nerd at exactly the right time and place so that it was possible to really impress adults with minimal actual effort

gosub1003• 2 years ago

So you thought of this idea yourself at that age?

jdenning8• 2 years ago

I mean, my dad had already got liquid nitrogen for us to play with on a few occasions, I think he suggested “something with liquid nitrogen would be science fair gold”..it doesn’t take very deep knowledge to understand that cooler is better for a cpu.

magicalhippo• 2 years ago

My 286 was nominal 8 MHz, but the red turbo button boosted that to 12 MHz. How far did you manage to push it?

daqnz• 2 years ago

The turbo button actually was used to underclock the CPU's speed, not increase it.

https://en.wikipedia.org/wiki/Turbo_button

copperx• 2 years ago

How did you overclock it??????

burnte• 2 years ago

You replace the crystal on the motherboard with a faster one. I did it on 386s and 486s. Adrian Black recently did it with a 286 too I think.

fortran77• 2 years ago

286 systems generally didn’t have programmable on-chip clock oscillators for the CPU. There was an external clock chip that generated the exact frequency needed for the CPU; sometimes there was another setting for a reduced speed for compatibility. If you changed this clock, you’d also disturb all the other I/O that depended on it.

I can see why you won! In the early 80s, just building the clock circuitry to generate arbitrary frequencies for the CPU only would have been quite an engineering feat.

rodneyknaap2• 2 years ago

I have one possible explanation for such a phenomena to happen that cooling might make a 286 run faster. What may have been happening is that cooling the CPU shifted the timing of the CPU which is very plausible, this may have affected the system control circuits that terminate the cycles if something was right over the margin of timing. In some cases a slight shift in timing may advance the terminated T_COMMAND of the 286 into one CPU clock cycle earlier. That could theoretically result in a significant faster performance. Imagine one T_STATUS and for example three T_COMMAND cycles, a total of 4 CPU cycles that were executed previously, shifting into one T_COMMAND earlier, this would result in 1 T_STATUS and 2 T_COMMAND cycles, and increase the efficiency of the CPU by 25%.

FatalLogic2• 2 years ago

What are "T_COMMAND" and "T_STATUS"? I searched but that terminology doesn't seem to be used much

tonetegeatinst• 2 years ago

Can't wait for someone like kingpin or gamers nexus to try helium over clocking....

Iv been trying to keep an eye out for used LN2 tanks and dewars on different used places so I can grab one for cheap.

Always wanted to try making dip and dots at home, and going for insane PR's over clocking.

fein• 2 years ago

dip and dots

Just replying for others because this confused the hell out of me until I said it out loud - Dippin' Dots, the ice cream treat you find at amusement parks.

NitpickLawyer• 2 years ago

tank youth for the bone apple tea!

rcxdude• 2 years ago

Can't wait for someone like kingpin or gamers nexus to try helium over clocking....

Basically only useful to say you did. It's way more expensive, and doesn't really help with cooling because once you're cryogenic the bottleneck tends not to be the temperature of your liquid. Also helium has a lower heat of vaporisation and heat capacity than nitrogen, so it could easily perform worse.

yjftsjthsd-h2• 2 years ago

Coming from Ubuntu in my SkatterBencher guide, there’s two things we can improve:
1. Change to the official Raspberry Pi OS

Now I'm curious how much OS matters. Has anyone done a bunch of benchmarks to see if the Pi is faster/slower on Ubuntu/RPiOS/Alpine/ArchARM/FreeBSD?

redundantly3• 2 years ago

I don't know if it still holds true, but historically speaking, Raspberry Pi OS has been the best option for out of the box performance.

geerlingguy• 2 years ago

Usually this holds true in terms of how quickly performance optimizations and bug fixes trickle down to other distributions.

Like the NUMA patch mentioned in the video-it is already included in Pi OS (and has been for a while, but it takes time for it to make its way into other distros.

yndoendo• 2 years ago

Don't know about present. Back when I worked with a version 2, Raspbian couldn't handle a 2560×1080 UltraWide without low frame rate with stuttering but ArchARM with Sway had no issues.

yjftsjthsd-h2• 2 years ago

I would be suspicious of that being the display server as much as the OS, though... although, granted, I suppose it depends on what the fair basis is for comparison. A person could argue that "performance of the default graphical stack" is at least as important as "performance of a CPU-bound workload if you tune everything else".

chakintosh• 2 years ago

I think you have a Pi stuck to your LN2 container

ramassnel1• 2 years ago

Holy shit.

ComputerGuru• 2 years ago

Am I the only one that was disenchanted with the article? It was basically and advertisement for Elmor Labs and everything was “swap out a part for an Elmor part configured to do the same thing”.

The cooling was basically for show given the temperature- and voltage-independent scaling wall; the proper place to go would have been an ARM-based development house to use the debug tools, they’re certainly available.

I’m not a Pi guy and I don’t know if the dev samples/hal/device trees have been released yet, but another option is to set up a bare metal environment and bring up the clock buses one by one to a different multiplier and see if you can reproduce it manually executing neon instructions in a tight loop.

rldjbpin• 2 years ago

the ln2 pot looks quite ridiculous with the board, but to be fair it seems less complex to make it work due to "blank" pcb around the soc.

while not mentioned in the article, i wonder if deliding the soc (as done previously here - https://www.jeffgeerling.com/blog/2024/new-2gb-pi-5-has-33-s...) could help with this.

3600 MHz Raspberry Pi 5 with Liquid Nitrogen

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