[rixrax]

But what about the heat sinks / fan when you mount the m2 on top? Especially /w Pi 5, to get more perf out of it, it presumably should have a sizeable heat sink complete with the fan?

[distances]

The Active Cooler part (that contains a heatsink too) fits well under the HAT.

[jsheard]

The fan won't do much if there a second PCB stacked right on top of it though, unless there's cutouts for it.

[distances]

It does quite enough. Some test results are here: https://bret.dk/official-raspberry-pi-m-2-hat-review/#Temper...

And for any moderate use cases the need for any cooler at all could be disputed. I bet most RPi use cases don't include heavy computing.

[zamadatix]

In what way is thermally throttling at 86.5 C quite enough cooling? "Active Cooler in Case with HAT" idles near the same temperature "Active Cooler" reaches under max, unthrottled, load.

[distances]

I think you misread the graph. "Active Cooler in Case with HAT" is pretty much the same temperature (74.8) as "Active Cooler" (no case, no hat, 70.6). None of the configurations with the cooler throttled.

[zamadatix]

Ah shit, you're 100% right. Looking at it on my computer monitor I think I was looking at the "Heatsink in Case with HAT" line color by mistake. My error and apologies!

[0x073]

A covered fan is not very clever and the rp5 need active cooling.