I had hoped I would be able to get my PINE64 CM4 working with Yellow and while it does work, I could never get GPIO working (or rather my ZW800 GPIO board). I recently managed to grab a 2GB Pi4 CM4 from pishop.us and finally have things up and running (with Z-Wave working too) and thought I’d share this interesting temp graph:
The pi4 (which just had a small heatsink on it in open air) is the data before 12:30. After is the CM4 in the Yellow case. It’s warmer though not by a huge amount. Does make me wonder if some vents might help though. Yellow comes with a heatsink for the CM4 (which I am using). Only about 4C worth of change so far, but also a bit early to draw conclusions.
I’m still hoping I can use a non-Pi CM4 (ideally a RISCV one if/once they hit the market) but it’s super nice to have a better enclosure with an nVME that sits on the shelf and is far less precarious than my Pi4 setup was.
The left or the right? I run quite a few ancillary tasks on it in addition to HA many of which tend to be at regular intervals, mostly telemetry related (like my outdoor weather sensors) which may explain the spikes. I don’t think the Pi throttles until 85C? The heatsink on the Pi4 would be warm but not hot. I can’t feel the heatsink inside the yellow with my hands of course since it’s closed but the top tends to be a little warm. I noticed the Yellow has more spikes in temperature than the Pi4. It’s all the same tasks so not sure there. On the old instance I didn’t do any underclocking or anything like that. As is common it seems trying to do all that on the Pi4’s only seem to save a few degrees.
Yellow just got fired up today so remains to be seen how well it does after running for days but so far I haven’t run into any issues. I would’ve liked at least 4GB of RAM but finding any CM4 in stock seems to be a blessing so I went for it.
I thought the Pi4 throttled at higher termperature too, but in the normal Pi config it was set to 50 degrees celsius and this safety feature had to be turned off specifically to have the throttling raised to 70 degress celsius.
The newest EEPROM firmware update also had an effect, so make sure you get that installed on the Pi4.
I guess this feature is to ensure that no damage is being done on a Pi4 without any cooling at all.
I have no idea about the Yellow, but compare the CPU load with the temperature on both setups, then you can see clearly if it is in fact throttling.
Turns out, I was measuring the wrong thing, whoops! Interestingly, the higher temperatures were still my original Pi4, just moved to my office. Because I was migrating everything in place (so all my URLs stayed the same) but also needed my old Pi4 online to grab a few things, I inadvertently still had it’s temperature reporting turned on. The actual CM4, even though the Yellow doesn’t have any vents, runs much cooler running essentially the same workloads:
