My idles are only about 10° above ambient on my 3600 with a Dark Rock Pro 4, but under load it can hit high 60's-low 70's. That's mostly because I only have the intake fans running as yet in my custom case, and the hottest GPU on the planet turning my case into a hotbox. On idle, neither the CPU or GPU are doing anything so there are no problems, but when folding they both ramp up and the temps on the GPU go close to throttling, which warms up the CPU as well. With the RX580 Nitro I have just replaced, the CPU would rarely get to 60° while folding, with the Nitro at full tilt and the CPU at 100% on all cores. I think the idle temp problems I too have occasionally heard regarding the 3600 are either a silicon lottery problem or a board/bios issue. I've only just switched from Asrock X470 Taichi to Asus X570 TUF though, and I think in both cases the CPU behaved similarly, so either neither of those boards are problematic or it is indeed a silicon lottery issue.