It runs cool and quiet. I'm writing this comment on one. Even benchmarking I can barely notice it most of the time. I had the fastest 2017 5K iMac at work for half a year before switching jobs and it would get louder and a lot more often than my i9/Vega 48. The only time I really notice it is Bootcamped into Windows running a game at 1440p around 60fps on medium to high settings (depending on the game) and the game audio gets quiet and then I'm suddenly aware. I noticed it ramp up to medium levels for about a minute maybe twice when I was first setting it up and it was downloading the iCloud Photo library, Dropbox, while installing Adobe Creative Cloud and doing a time machine backup, spotlight index with several other apps open being configured at the same time and the App Store also installing things in the background. Since initial setup I've run Cinebench R20, R15, Geekbench, and some heavier tests in Premiere Pro stabilizing 4K footage and Photoshop rendering a 22GP (yes, gigapixel) oak tree and yeah, it's not loud.Nothing about thermals or fan noise?