Questions regarding temperature


#1

I’ve recently upgraded to CM3 and in the process of getting a suitable heatsink to keep temperature under control. Which brings me to the question of what the acceptable temperature will be. Given that I have a WD Red 1TB inside my Slice, is 60-66 deg C processor temperature an acceptable working range? This is the temperature I have with the CM1 installed without a heatsink (I’m not even going to talk about CM3 temperature without the heatsink :slight_smile: ) With the heatsink I’m expecting CM3 temperatures to be around the same given the ambient temperature and placement of Slice.

Thanks !


#2

It depends on your ambient temperature as well.

With an ambient of around 20 deg C my Slice with CM3 and a 2TB Samsung drive idles at around 40 deg C, and if it is stressed (say playing back some h.265 content in software) the temp rises to around 50 deg C.

Once it’s idling again the temp drops back down within a minute or two.

Hope this helps.


#3

@sarathchandars

several different designs here http://forums.fiveninjas.com/t/new-raspberry-pi-3-coming-soon/1206/160 and here http://forums.fiveninjas.com/t/slice-cm3-cooling-mods/1433/6

The result from these very different solutions is as @shutterbug says.

The consensus (including Gordon of Five Ninjas fame) is that the CM3 needs some cooling and because of the nature of the closed design, the heatsink needs to be contacting the case to “let the heat out”. The reports of temperature with heatsink are maxing out around the 50 deg C mark when fully loaded CPU, so that is what to aim for. Without heatsink the CPU will throttle above 80 Deg and my naked slice https://shop.pimoroni.com/products/slice-light-kit CPU temp gets there and throttles within a few minutes of max CPU, and that is exposed to the air. With a heatsink it is well managed.

Without any heatsink I would be a little worried about internal case temperature increasing the hard disk temperature. HDDs don’t like getting too warm, tends to reduce their lifespan.

Let us know what solution you implement, with a picture too :slight_smile:

Roger


#4

Thanks @g7ruh and @shutterbug. My experience has been along similar lines - while I was scraping the library afresh, the CPU had to throttle down (Kodi even displayed the dreaded thermometer icon!).

I’m not designing any special heatsink. Another Slice user - @rahuljawale - has worked out a 15mm x 15mm x 12mm copper block that I intend to get and install. What I was looking for more was along the lines what would be an appropriate temperature to aim for - to not risk shortening the life of the both the CM and the hard disk. I experience ambient temperatures of around 28-30 deg C, and CM1 used to top out at 67 deg C while playing 20GB MKV files.

If I end up with 67 deg C, I’d try to work out placement to cool the box after heatsink installation to try to take it down further.


#5

As long as the temperature remains below 85 degrees then the processor will be fine for a 10 year lifetime.


#6

@Gordon That clears everything for me. Thanks…