The passively-cooled Asus TUF RTX 3080 GPU was tested in Furmark along with a Ryzen 5 5600X and the results were a bit sketchy. While the CPU was running at 40 degrees Celsius during the Furmark test, the GPU peaked at 87 degrees Celsius and it did not even level out. Total power draw appears to hover around 410 W, most likely in idle.
https://www.notebookcheck.net/Fanless-RTX-3080-spotted-inside-a-silent-mini-PC-build.522528.0.html