Don
I wonder if it'll run any cooler than the 5800X3D I was impressed how much cooler my 5700x was over my 5800x
Same here, I got the 5700x as it was at the limit of my desired TDP.
Eco mode on a 5800x drops the TDP and essentially turns it into a 5700x anyway. I got a great deal on a 5800x for my son's PC at Christmas, was worried as his case is fairly rubbish solid fronted rgb aerocool - activated eco mode and temperatures were absolutely fine afterwards.
(If he ever swaps cases or gets an upgrade then at least I know there is a little bit of performance left on the table that can be unlocked)