Idle temperatures aren't all that meaningful to me, and sensors tend to become less accurate the further they are from TjMax, but here's mine at the moment via Adrenalin.
Oddly, ever since a few BIOS updates ago (early 2024), certain software (GPU-Z, Libre Hardware Monitor, Afterburner, and maybe others) hasn't been able to read the temperatures and/or clock speeds of my CPU and/or GPU. Adrenalin and HwInfo64 seem to be the only ones that do now.
I'd say that's pretty representative of average idle though. Usually I have stuff open/active which will push those up.
CPU: Ryzen 7 5800X3D (stock, no undervolt at all.)
CPU temperature: 37.8C
Memory: 4x dual rank DIMMs at 3,600 MHz/1,800 MHz Infinity Fabric, in case this has a small impact on CPU temperature which it probably does.
Cooling: Dark Rock Pro 4 (whatever default fan behavior that my motherboard is giving it, I just know it's always nearly silent.)
Case cooling: Fractal Arc Midi case with 2x intake fans (front) and 3x exhaust fans (rear and top), and I have the few connected to the case set at 7V so perhaps there's room for better cooling; I prefer lower noise and good enough temperatures over absolute lowest temperatures.
Ambient: ~27.5C (~81F) so it's a bit warm right now, yes. Late summer/going into autumn.
I really don't watch these things as much as some others around here probably do, but I watch them enough to get an idea of what it's doing to make sure everything isn't too far out of line.
In games, the CPU seems to typically be around the 50C, 60C, or 70C range depending on amount of cores under load. Some higher core loads/games push that into the 80C range. Cinebench is ~85C I think, and Minecraft with Distant Horizons in particular while generating LODs might be the heaviest I've seen as it pretty much has it constantly at TjMax (I never see it report that it is throttling at this point though, but it acts like my old GeForce did at 83C where when it reaches that point, it stops going higher). I've never seen anything else push it as high, not even supposed benchmarks or stress tests. A lot of people like to dismiss stress tests or all core loads and go "in real world use and games it's going to be quite a bit lower" but apparently that's not always true. The worst case scenario you've discovered your CPU encounters is ultimately what matters most. Idle is as far away from that as it gets, so ultimately idle doesn't matter to me.
