[mcovalt]

> I was able to work around most of the cooling-related issues by mounting the laptop vertically...

Have you happened to measure the thermal difference vertically mounting your laptop? I also vertically mounted my home server laptop for the same reasons, but noticed the fans seemed much louder so I returned it to be horizontal like normal. It's as if they were designed so that the horizontal surface acts to attenuate their high-frequency sounds. It's still annoying, but less so. I'm wondering if going vertical again, but throttling the CPU as you've done is the way to go.

[hddherman]

I don't have any measurements other than the general observations that I shared in the post. It should work better than having it lie down on a wooden desk, for example, as that greatly limits the cooling potential. You only have a tiny gap where the air can move in.

It might be that your fan might be old and worn out. As someone who uses older laptops and has given out T420/X230 type machines to family members, I've noticed that sometimes tilting the laptop under use results in vibrations coming from the fan, likely from it being worn out and the blades touching the heatsink and/or plastic.