WildW wrote on 2017-09-23, 05:42:

I assumed it was quite common to see CPUs of this era with only a passive heatsink, so long as the CPU is close to the PSU fan. I have a couple of Gateway systems like this, one P233 MMX and one PIII 450, both are super quiet.

The large passive heatsinks were quite common, especially with large OEMs. What I noticed back then was that especially the Pentium 1 era machines often had anodized heatsinks (commen were green, blue and the very dark purple that was almost black (kinda same purplish color that 486 Intel Overdrive heatsinks have).
Even a lot of active HSFs were anodized. This kinda stopped when Slot 1/ss7 became the norm.

I've always kinda wondered what the story was behind these colors.

I seen this work on a Pentium MMX at 133MHz on 2.2V. The CPU was specified for 2.8V.

Cheers,