[sgarland]

The massive noise difference between brands, models, and generations of rack servers is astounding to me. I have five rack servers in my house, not in a closet. Three are Dell R620s, one is a Supermicro X9, and one is a Supermicro X11. The Dells are 1Us and by all rights should be screamers, but they aren't. The Supermicros are 2Us, and while they weren't screamers, they were loud enough that on the one that's on 24/7 (the X11), I swapped the PSUs for quieter models, the CPU fan for a Noctua, and throttled the case fans. When the X9 boots up to ingest ZFS snapshots, you can definitely tell it's there.

I used to think the R620s being bizarrely quiet was because homelab loads are understandably small, but then one day I got well over half the cores to 100% sustained doing something, and it didn't get any louder. I know they _can_ get loud, because at boot the fans go to 100%.