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Comment by iamtedd | Hacker News Reader

This is pretty bad:

"Does Raspberry Pi 5 need active cooling?

"Raspberry Pi 5 is faster and more powerful than prior-generation Raspberry Pis, and like most general-purpose computers, it will perform best with active cooling. The Raspberry Pi Case for Raspberry Pi 5, with its integrated fan, is one way to provide this."

They pose a question themselves, and don't even answer it. Of course something will perform best with active cooling. Does it need it?

I don't need this wishy-washy marketing language from Raspberry Pi.

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I hate it when someone answers a yes/no question with something other than yes or no.

Here’s my proposed edit:

Q: "Does Raspberry Pi 5 need active cooling?

Original A: "Raspberry Pi 5 is faster and more powerful than prior-generation Raspberry Pis…”

Better A: "For modest workloads, no. For heavier workloads, you will get better performance with active cooling. Raspberry Pi 5 is faster and more powerful than prior-generation Raspberry Pis…”

It literally tells you that you don't need cooling, but if you add it you'll get more performance.

I don't find it hard to understand what this means: the soc limits it's core performance based on thermal conditions and will throttle when hitting limit temperature. That's standard behavior on every computer or smartphone or GPU out there.

Make temperature lower and it will clock and run at higher speeds without throttling.

Are we reading the same blog post? The post that parent posted literally reads:

> "Raspberry Pi 5 has been designed to handle typical client workloads, uncased, with no active cooling".

No, I'm reading the posted product page. Where all the important, technical (considering the product) information should be.

'uncased', which is the problem with many boards for the hobbyist market, from compute to sensors.

IMHO, uncased means you're doing maintenance or it's a toy, but it's not a 'production' configuration.

They can't tell you how the board will behave on any random case you decide to put it on.

The uncased requirement is exactly what I'd expect to see there. Other than that, only if they decide to get really technical (they should) and tell you dissipating power / °C and temperature limits.

The answer is nuanced. It can run workloads somewhat faster and cooler than Pi 4 without active cooling. But it also can't reach close to its peak performance without active cooling.

Your answer is more direct and uses fewer words. Can you help them fix their product page?

Probably not ;)

The actual info I'd rely upon at this point:

https://www.phoronix.com/benchmark/result/raspberry-pi-5-coo...

pi5 with active cooler is about 1.2-1.5x faster than pi5 without cooler for most workloads that care than without.

Pi5 with active cooler is about 2-2.5x faster than Pi4. So Pi5 without cooler is probably about 1.5x faster than pi4, depending upon workload. (And more than this for quick bursts where thermal mass wins).

And if you dont have a heatsink and fan of sorts just use alternativing fingers on the cpu, they can still absorb about 10-15 DegC off the cpu temp and thats overclocking a 3b in the 1.35Ghz range. Surprisingly robust. Sadly cant get it to idle below .6Ghz yet, that needs more work.

But it makes wonder how much more phone manufacturers could squeeze out of their phones, although Apple are definately overclocking the 15.

Should we get Intel and AMD to clarify their product pages at the same time?

Haha - and while we’re at it, might as well start putting labels on Apple’s performance graph slides :-)

Does that mean for the same load the power requirements of the pi5 are lower than the pi4?

Yes, that's what they directly claim. Phoronix's measurements seem to (indirectly) bear this out. https://news.ycombinator.com/item?id=37686214

"The combination of a newer core, a higher clock speed, and a smaller process geometry yields a much faster Raspberry Pi, and one that consumes much less power for a given workload."

It depends on what "need" means. I'm pretty sure you can take a 400W TDP Threadripper and run it without active cooling. It will throttle down to run at whatever speed (well, TDP) that doesn't fry it. The Raspberry Pi does the same thing.

If your goal is to get the highest score on every benchmark, then yeah, you need active cooling. That has been true on every Raspberry Pi, I think. (I don't remember if the 1 needed active cooling. I did not have any. I also remember it taking over a day to recompile Linux! Still faster than setting up a cross compiler at the time ;)

Threadrippers use 50W+ at idle, so no, it won't just "throttle down"

Mine uses about 80, but yeah, you can get rid of 80W passively. Consider a 100 watt incandescent light bulb; no fan!

And how hot does the bulb get? Googling yields "The surface temperature of incandescent light bulbs varies from 150 to more than 250 degrees" (https://www.pacificlamp.com/temperature-of-a-100-watt-bulb.a...). Which, googling says, is likely hot enough to damage a CPU.

150F is like 65C which loads of CPUs run fine at. Going past 212F (100C) is usually where you'll start having problems with a lot of common desktop processors.

"peak power consumption increases to around 12W, versus 8W for Raspberry Pi 4"

A beefy heatsink case should be able to handle that.

I think they answer your question in the PSU section “Raspberry Pi 5 consumes significantly less power, and runs significantly cooler, than Raspberry Pi 4 when running an identical workload.”

That's not documentation of any reasonable level though.

An MPU designer expects to see something like "200mA draw from the 1.2V power-domain when running at 400 MHz" or "10mA draw from the 1.2V power-domain when in first level of sleep". (Maybe not this small since Rasp. Pi is a more powerful chip, but... you know... actual specifics).

Not on the linked page.

"Will my Raspberry Pi 4 power supply work with Raspberry Pi 5?

"Raspberry Pi 5 is a higher-performance computer than Raspberry Pi 4, and you may have problems using an under-powered supply. We recommend a high-quality 5W 5A USB-C power supply, such as the new Raspberry Pi 27W USB-C Power Supply."

The question asks about power requirements, but the answer is about performance?

The first time I read that I thought the 5 needs more power than the 4, not less.

> we recommend a 5w PSU like our new 27W PSU

Ermmm, what?

It’s a typo: They mean 5A I think.

It's clearly a typo, and should be 5V.

But then you get 5V 5A ... 27W that is clearly incorrect too. So my guess is nobody is proofreading the technical specifications, and everybody that cares was kept away from that page.

5V * 5A = 25W, no PSU is 100% effective so 27W is reasonable requirement

I expect it is 27W to support 9V 3V, not because of tolerances per se. (Source https://www.sparkfun.com/products/23583)

You don't specify a PSU by its energy consumption. You specify it by output.

Also, that 92% efficiency, is believable, but a bit high for a 5V 5A PSU (this is a difficult combination). I would expect any such unity to be marketed as high-efficiency.

I think the question is actually: "can I safely (like it's not going to melt or catch fire) use the RPI5 under any load without active cooling) ?".

Sure, you can.

If you frequently work it really hard, it'll have larger temperature swings and may fail earlier, but it'll still probably last quite awhile. The failure is not likely to be catching on fire.

requiring cooling limits the use case. (remember, they've sold > 30 million of them)

I'm pretty sure what it means is that kids who use the pi on their desk don't need to spend on a cooler. It will probably throttle and run slower.

Meanwhile an adult using the pi could put on a cooler and wring lots of performance out of it.

Another reason not to buy it.

Who hurt you?

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