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Comparing Raspberry Pi stats: CPU temp & RAM

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Continuing the discussion from Emoncms v9.7 - Emoncms admin Raspberry Pi system stats & reboot:


Here is a screen grab of the stats my emonPi:

  • Raspberry Pi 3
  • Connected via onboard Wifi
  • Ambient temperature approx 15 deg C
  • emonSD-03May16
    • nodeRED
    • OpenHAB

I’m interested to find out how these stats CPU temp, RAM usage etc compared to other users also running an emonSD? I’m not particularly concerned but a CPU temp of 43 deg C seems quite warm given the ambient temp of about 15 degC!

Hi Glyn,

I recently put a node in node-red to read the Pi temperature and log it to my local emoncms. This is a Pi zero with 9.31 (I think) installed following the raspi installation instructions on Jessie Lite. I’m running MQTT and node-red as well as emoncms but not much else. So a similar system to yours.

The Pi temperature averages 40C within a degree or so and I think if you’ve read the Pi forums you’ll find that Pis run warm all the time, so I reckon around 40C is fine. I guess if you are doing heavy compute type applications then it would run hotter but with the stuff we are running it’s hardly ticking over.

Simon

PS My system runs on a USB HDD but I wouldn’t think this would matter much.

PPS no RAM usage, guess I ought to check some time but while things are running fine, I’m not that concerned about that.

I have an AVG of 40deg.
I use latest emonSD on a PI2

The CPU temp is probably as expected in it’s case, for re-assurance check this video
My Pi2 runs at 35 deg, but it’s on a HDD and a (very well) ventilated case.

Paul

The metal emonPi case should be better at heat than a plastic case, there is actually quite a bit of space in around the RaspberryPi. The Pi3 does get much hotter than the Pi2

here are my numbers:

EDIT: mid-2015 emonPi. 8GB SD card. Left end panel removed to make changing SD cards easier.

  • Raspberry Pi 2
  • Connected via ethernet
  • Ambient temperature approx 20 ºC
  • emonSD-03May16
  • nodeRED

This is a 2015 EmonPi still using the supplied 4Gb SD card:

The system is in a garage on a NW facing wall, ambient currently 13C. I also put a spare DS18B20 on the heatsink fins of our SolarEdge 5K inverter next to it and am surprised to find it never gets above 35C !

Thanks OEM team and all contributors for a really good system…

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Good to know my Pi is excessively hot.

Interesting to see that @derekb has slightly lower total RAM than me and @Jon

The Pi’s are reportedly good up to 55C, I managed to push one to 50C when testing a very small Pi case.

I think 43 is a bit high but not a huge concern. I have one Pi that I monitor runs at a constant 43C, although the loading is quite light the Pi2, RFM2Pi, 3x emonTxs and 4x wallwarts are installed in a snug sealed box in a warm plant room, but the Pi only runs emonHub for forwarding only

The RAM difference will be the gpu_ram allocation reduced from 64 to 16 Mb on recent images.

Ah, good point :thumbsup: