Beating Jeff's 3.14 Ghz Raspberry Pi 5

https://jonatron.github.io/randomstuff/pivolt/

by jonatron • 2 years ago

229 60 2 years ago

jonatron.github.io

dustfinger• 2 years ago

Assuming a fast reliable internet connection, how well does an overclocked raspberry pi 5 perform when video conferencing using popular conferencing applications such as zoom, google meet, ms teams and the like?

godzillabrennus• 2 years ago

Probably slightly worse than a 10 year old core i7 cpu computer.

matt-p• 2 years ago

True, to some extent this is also an artefact of (comparatively) poor software optimisation for pi. In this case almost certainly zoom and others apps will be using cpu encoding/decoding rather than offloading.

justin66• 2 years ago

Teams works fine, so I suspect the others do as well.

bdavbdav• 2 years ago

For that kind of thing, you’re 100x better off getting an old enterprise uSFF workstation on the cheap. Whenever I can, I reach for a used Dell 5070 or similar if I don’t need GPIO. They eBay for about £40-50, have real NVME, x86, and the pentium ones are pretty powerful.

geerlingguy3• 2 years ago

Awesome work, and I'm glad you could post some results! I'm hoping to get time to delid one, put on a peltier cooler, and try to control the temperature a little better for a run to see how high it'll go before either burning up or going unstable.

From my testing on clocks on the Pi 5, it looks like the default clock of 2.4 GHz is pretty close to the sweet spot for this chip (BCM2712), and you burn a lot of power for small incremental gains after that[1]. (Which you seem to also show with the 3.3 GHz overclock!).

I also spoke to one of the Pi engineers about the chip behavior at higher clocks, and he suggested unlike some chips, this chip might run more stably at higher temperatures (like 50-60°C) rather than 'as cold as you can get it'. So that poses some challenges since most cooling solutions aren't tuned for 'keep a temperature' but instead 'get it as cold as possible', without a lot of manual tweaking.

[1] https://www.jeffgeerling.com/blog/2023/overclocking-and-unde...

metadat3• 2 years ago

Did the engineer explain why the higher temps contribute to stability? I've not heard of such a phenomenon before.

geerlingguy3• 2 years ago

No physics-level explanation, just that they found the chips to be more stable in testing when they were a little warmer vs a little colder. The key was to keep them around that temperature, though, which still requires a good amount of cooling the more voltage that runs through it!

Just... he mentioned I might not have as much success using LN2 or something more exotic, compared to standard water or Peltier cooling.

c0balt• 2 years ago

This might be naive but you may take a look at warm water cooling from HPC/ Hyper Scalers. Combined with a custom block this should stay stable at the 50-60° sweet spot.

fl0ki3• 2 years ago

but instead 'get it as cold as possible'

More like 'get it as ambient as possible' so if you're in a 50 degree room you're all set.

trvz• 2 years ago

You've mixed up Celsius and Fahrenheit.

tonetegeatinst• 2 years ago

I find myself disappointed in the lack of helium cooled silicon chips in the modern year of 2024.

mrlonglong• 2 years ago

I'd love to see a 16GB variant of the RPi5 some day.

Havoc2• 2 years ago

If you don’t need the pi software ecosystem the orange pi 5 plus competitor comes in 32gb

jonatron6• 2 years ago

Just quickly looking at Orange Pi 5 images without properly researching, the official site links to images on google drive, and armbian has an image with a 5.10 kernel, that requires PPA's for 3D acceleration.

There's got to be an SBC other than Raspberry Pi that has reasonable software support. Does anyone know? I'm not buying another SBC that advertises hardware video decoding but doesn't actually have the software for it, or requires one specific modified kernel version.

fl0ki3• 2 years ago

Is there a consensus on the best available cooler for the Pi 5? I looked at this exact unit but wanted more of a "case" design.

I first tried the Flirc passive case. It seems to transport and dissipate heat notably better than active coolers with copper heatsinks and 4000 RPM fans. That's especially impressive given that the entire top and bottom are plastic, leaving the horizontal edge as the only surface for heat dissipation.

My remaining concern there is that it only cools the Broadcom SoC, while creating a nice little insulated oven for the other chips. The inner surface area is much greater than the outer surface area, and with no ventilation by design, so heat from the SoC is being distributed throughout the whole inner volume.

I also tried an active cooler to avoid that, which I'm sure is better for every other chip but I'm surprised to find was substantially worse for the SoC itself. I guess the tiny copper block gets saturated very quickly and its surface area isn't very large for air cooling.

Maybe that's why the monoblock passive coolers do so well, in theory they combine the best of these approaches. I just wish they'd apply the same idea to a refined "case" design like the Flirc.

LeoPanthera• 2 years ago

I also use the flirc cases and have been similarly concerned by the other components getting hot, but I must admit that it doesn’t seem to cause any actual problems, at least not yet, and it certainly does a good job of keeping the CPU cool.

rolobio• 2 years ago

I have always found coolers with heat pipes provide the best cooling for mine.

wpm• 2 years ago

if you don't need the pi to stack I've found the Argon One to be a good case for both overclocked 4's and 5's. The fan is somewhat weedy and the airflow is questionable, but the entire case acts as a heatsink. As far as thermal mass goes I don't know of any that beat it.

And additionally, you get a Pi case that puts all the ports on one edge where they belong instead of forcing you to make cable squids on your workbench/desk.

nsteel3• 2 years ago

The bigger the better, right? If so, this: https://thepihut.com/products/ice-tower-plus-for-raspberry-p...

mbesto• 2 years ago

There's a silicon lottery

Isn't there also an environmental factor that hasn't been fully explore? Are we sure there isn't an alternative to the cooling mechanism on the CPU than the two options the parent and Jeff used?

486sx33• 2 years ago

Don’t know anything about arm or pi cooling But on my ryzen 9, a big ass air cooler beats liquid cooling by miles.

zamadatix• 2 years ago

Liquid cooling itself doesn't really cool anything, it's actually all about being able to move heat around so you can have an absolutely insane amount of radiator because it doesn't have to fit in the space around the CPU. If your radiator isn't enormous (i.e. at least 360mm, if not larger), is too thin, or is itself not getting proper airflow to actually dissipate the energy then it's probably not doing much better than a large air cooler could do. Well the other thing liquid loops add is they give a larger thermal mass (i.e. takes a lot longer to heat up and can absorb bursts better) but that doesn't really matter 2 hours in.

Also a 7950X owner :). It's been a good CPU outside the memory controller is a bit weak compared to the Intel counterparts, will be interesting to see what the two release this year.

hinkley• 2 years ago

How much voltage noise can get from a PSU to the cpu these days? I wonder if a better one lets you get closer to the theoretical limit.

KennyBlanken• 2 years ago

Semi-related, but TIL the Raspberry Pi Foundation enabling large corporate customers to secure-boot lock the Pis they're embedding in their juice dispensers and whatnot.

Nothing like being a supposed open source darling and helping corporations deny people the right to use hardware they purchase, the way they want to - and helping contribute to e-waste, because there will be millions of Pis that nobody can use for anything other than the IoT banana dispenser they were integrated into...

jonatron6• 2 years ago

I'm not sure Raspberry Pi are to blame. Broadcom insist on closed source binary blobs, and their chip has e-fuses built in.

regularfry• 2 years ago

I think it is reasonable to criticise them for being quite so tightly tied to Broadcom, though. That's an artefact of the local ecosystem they're in, and it's arguable that the pi wouldn't exist at the price point it does without such a close tie, but live by the sword, die by the sword...

im3w1l• 2 years ago

There are legitimate reasons for such a thing though, I think. Like I don't want my juice dispenser to do general purpose computation. I don't want it to be capable of web surfing.

Ideally you would do that by building it out of simple mechanical components, but if taking smart components and dumbing them down is cheaper then that sounds fine too.

nsteel3• 2 years ago

Nothing like being a supposed open source darling

They've never claimed to be an open-source company. It's unfair to judge a company (or charity) against your own ideas of what they stand for. Some of their software is open source and some is not. Some of their hardware is open (2040), most is not.

Zamiel_Snawley• 2 years ago

Can you say more about where you found this information? I didn’t see it in the OP.

I think rpi has made some compromises to advance business viability, which feeds their more altruistic endeavours.

jonatron6• 2 years ago

This PDF https://pip.raspberrypi.com/categories/685-whitepapers-app-n...

benatkin• 2 years ago

Another thing that won't be matched by Tau Day.

whalesalad• 2 years ago

pi's feel like the perfect candidate for submerged liquid cooling. imagining a tiny little french fry basket filled with pi's being lowered into some mineral oil and bubblin. salt to taste.

elliottkember• 2 years ago

raspberry fri

MuffinFlavored• 2 years ago

A single mov.cc instruction can be patched to remove the voltage limit. However, it's in bootmain, which is signed, so we can't just patch bootmain and flash the eeprom. However, as a root linux user on Raspberry Pi full access to system memory, including memory used by the videocore. I mmap'd /dev/vc-mem, searched for the instruction and replaced it, but i'll leave that as an exercise to the reader. I don't want people blaming me if their Pi decides to halt and catch fire.

Does this need to be reapplied every time at boot? Guessing yes...

jonatron6• 2 years ago

Yes. Maybe it's theoretically possible to add something to a modifiable part of the eeprom, but that's beyond what I can do in my spare time.

magicalhippo• 2 years ago

I don't want people blaming me if their Pi decides to halt and catch fire.

For those who didn't catch the reference:

https://en.wikipedia.org/wiki/Halt_and_Catch_Fire_(computing...

Beating Jeff's 3.14 Ghz Raspberry Pi 5

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