What do I need to go with a Pi 4

I am running a Pi4, two SSDS and a TV hat with no cooling. So far its OK. One of the SSDS gets a bit warm.

The pi itself comes out well below 'temperatures of concern'

If you're buying the Pi4 then why not go for a Pi5, there's very little difference in the price.

I've run two Pi4 systems without heatsink or fan for a very long time with no issues at all. I've just looked at one of them, it's been running at least since May 2023. As I understand it anyway the system will simply slow down if it thinks it's getting too hot.

In article (Dans l'article) snipped-for-privacy@ku.gro.lloiff>, Adrian snipped-for-privacy@ku.gro.lioff> wrote (écrivait) :

And with USB C connector !

I get

- for mini HDMI -> micro HDMI I get

-for VGA -> micro HDMI I get

I don't have nor use that.

Adrian,

No problem with the other suggestions.

When you say "starting to struggle" what have you measured? Are you running out of memory, CPU power, disk I/O, or network I/O? I think it would be useful to know what exactly in your system needs changing.

It's possible that a Pi 3B+ might be a sufficient upgrade (but can you still get them?).

The Pi-5 creates quite a bit more heat than the Pi 4, and has some software compatibility issues, so unless you really need the 5, stick to the 4. (I have both here). If you are not running headless, the Pi 400 has a heatsink and keyboard built in. I have a couple here and have been very pleased with them. One even runs both Windows and Linux, that's using the Twister OS. It uses about 2 GB of its 4 GB memory, and averages 10-12% CPU.

nearly twice the price for entry level.

...... ...

AIUI that is the case

When you are using it in 'burst mode' to do something compute intense it will get hot.

But not that hot... :-)

Can in uk at the moment. all sorts.

I think that's a good point

If you are not running headless, the Pi 400

The Pi is run headless in the normal way of things, but being able to connect a keyboard, mouse and monitor is helpful for the initial set up.

I monitor (every minute), CPU usage and temperature, as well as free memory (in addition to time to ping the router, space used on the SD card and SSD, bytes in/out and logical block access on the SSD). I can also see (using ls) how long it takes for the graphs (as png files) to be created.

On Sunday, I updated matplotlib (hoping, and failing, to fix a rendering problem). The previous version was ~2.5 years old. Since then, the time taken to generate graphs has risen enormously. What had taken ~5 minutes is now taking 12, which isn't good when you do it at a 10 minute interval. Saturday's CPU usage was a fairly typical 0.01 3.27 0,65 (min, max, mean), whereas yesterday's was 0.15 9.24 3.92. Memory usage doesn't seem vastly different, and CPU temperature was slightly lower, although that is to an extent governed by the ambient temperature, which has dropped slightly. The other resources appeared to be normalish (they vary a bit anyway). So from what I can see, the problem is that I'm badly lacking in CPU power rather than other resources.

The rationale of looking at a Pi4 rather than a Pi3, was to make a jump ahead so that I've got some spare capacity on the Pi, which gives me room for further expansion, which I'm likely to need in the near future. For no obvious reason, the Pi5 hadn't entered my thought processes.

Thanks

Adrian

Pi Hut:-

You can't get a 1Gb Pi 5, until recently you couldn't get a 1Gb Pi 4. If I was buying a Pi 4 now I wouldn't go for a 1Gb one.

Yes, but a 1Gb Pi 3b costs more than a 1Gb Pi 4 so there's not much point in buying one unless the lower power consumption is really important.

When idle there's little difference, e.g. :-

"We also ran a test to measure the heat generated by the devices during use. The comparison shows that both Raspberry Pi 5 and Raspberry Pi 4 generate similar amounts of heat. In terms of power consumption, the PI4 and PI5 have similar power consumption when not running programs. However, during video playback, there is only a small difference of 0.2 watts in their power consumption."

The Pi 5 *can* use more power but when doing the 'same thing' the power consumption is pretty close to that of the Pi 4.

I support that. I have been using a Pi4 8 GB with SSB, and replaced it with a Pi5 8 GB. Don't know what you will be using it for, but for web surfing there is quite a difference. The Pi4 was just too slow at reloading webpages, so I had to steel the PC from my wife. With the Pi5 there is not much difference from a newly built PC, concerning web surfing. Both Pi4 and Pi5 are in Flirc no-fan cases, and the temperature is not high. 60 degrees are seldom seen.

I forgot to mention that the Pi5 needs a 5 amp powersupply to be at its best.

I did. Running _headless_ it is more than enough.

$ free -m total used free shared buff/cache available Mem: 907 257 297 3 418 650 Swap: 99 0 99

I sometimes run short of CPU, but never RAM

---druck

I do the similar data gathering on my 16 Raspberry Pi's (a mix of 0W,

Only the single core Pi Zeros show any significant latency when reading a few dozen DS18B20 single wire temperature sensors, the Pi Zero 2W and Pi 2B run at the same clock rate, but benefit from the extra cores.

That's quite a lot of time for rendering. What I do is on the Pi is run a Python uwsgi program which process all the data which has been stored in sqlite3 databases, producing a bit of HTML and Javacript which utilises google charts to the the plotting. The processing takes the Pi

Perhaps you could also perform the rendering on a meatier machine too.

---druck

In message <uv4991$efer$ snipped-for-privacy@dont-email.me, druck snipped-for-privacy@druck.org.uk> writes

I did think about that, but that would mean leaving one of my PCs on

Adrian

I've been looking at fan cases, but they all seem to prevent the use of the HAT, which means I won't be able to find out what the ambient temperature is. I suppose I could design one of my own.

Adrian

On Pi4 I use the Argon ONE V2 case - good case with sensible fan. I have a V3 for the Pi5, excellent with their M2 bottom. Both available from the Pi Hut UK

Get a PC that's as low powered as a Pi, there are such beasts around nowadays and you can even find quite cheap refurbished ones. I like Fujitsu Esprimos, my desktop machine is an Esprimo P910 which is getting rather long in the tooth now (and consumes 18 watts at idle). I'm getting an Esprimo Q957 to replace it, that idles at about 5 watts. There are lots of different models with different capabilities and you can find even lower power ones than the Q957.

Not where I have worked...

Many years ago a small piece of equipment I had designed, housed in a totally enclosed steel rack mount case failed after it had been on for over a day.

It came back to me. It was working perfectly.

So I left it on for a day in the lab with a thermometer probe inside, It got to well over 90°C inside.

Beyond the upper limits of the commercial chips it was built from. They were well over 100°C case when opened it up.

We changed the case design and punched some air holes in it, and the problem never reoccurred.

There are three relevant points here.

The first is that silicon chips themselves survive extremely high internal temperatures. I have had a power Schottky diode unsolder itself when connected across a battery. The chips will generally suffer permanent damage at somewhere around 180°C . Which is a good thing since they are soldered to a board using hot air at a lot more than that.

The second thing us that they will start to exhibit seriously out of spec. behaviour at their rated *ambient* temperatures - usually +75°C for ICs. Inside the chip may well be a lot warmer than that.

The final thing is to understand the difference between a closed box, thermal convection cooling and forced air cooling. the is roughly a

How many Pis are in *closed* boxes *without* fans?

It's less an issue of 'do I need a fan?' or 'its 40°C ambient' than 'is any hot air going to escape?'

With case temperatures up to well over 100°C possible for power devices, the difference to an ambient of 40°C is not the much worse than say,

And a Pi draws somewhere in the 3-5W region. And has lots of board surface area to dissipate that.

From the Pi forum

"I have put the Pi4 in an airtight enclosure (with a big passive heatsink), locked the frequency to 1500Mhz, overvoltage=4 and have cpuburn running for about two hours. Ambient temp inside the box is 54 degrees celsius now.

vcgencmd measure_temp and vcgencmd measure_temp pmic show:

Pi4 CPU temp=124.0'C Pi4 PMIC temp=129.7'C

And it's still running fine, have a chromium open and can surf the web. I'm quite amazed."

And complements what I am saying, that only in a sealed enclosure where no convection is possible can you get to super high temeperatures, and in normal use the CPU will in any case throttle back

If you are going to run the Pi

That is a very hand wavey statement.

Passive cooling in a car in the sun with the windows closed yes, passive cooling in a well ventilated case in a room at 40°C, no way.

Personally year of designing high power audio amplifiers and dealing with computer hardware says 'bullshit'. You simply don't need fans for a board doing 5W. You can get that out of a single small transistor with a heatsink clipped on it. You can get that out of a TO3 packaged power transistor with no heat sink *at all*.

And a PI4B board is a *lot* more surface area than that.

Currently this rooms is at 24.2°C according to a thermometer equipped pico PI and the resident 4B that is in free air is showing this:

me@Coriolanus:~$ vcgencmd measure_temp temp=53.5'C me@Coriolanus:~$ vcgencmd measure_temp pmic temp=45.8'C

So at idle -ish the chip internals are 29.3°C - call it 30°C over ambient.

at 40°C ambient the chip internals will be up around 70°C.

That is nothing.

"we throttle the CPU when it get to 85 to keep the temperatures down. I've never seen anything over 90 in normal usage"

Is what the Raspberry Pi engineer says the chips do, in that thread I referred to above.

In short *unless* you put the pi in an airtight case and wrap it in insulation or leave it in the midday sun, it doesn't need a fan.

But people are just used to old school SPARC and INTEL chip that kicked out upwards of 50W at idle, needing a fan. In hard use some SPARCs would draw up to 300W!!!

Of all the customer returns on SPARC workstations I can remember they were all dead fans or dead cpus (with dead fans as well).