How do I debug NVME SSD heating while idle when booting from it?

nvme smart-log /dev/nvme0n1 shows consistently climbing temporature of a KINGSTON SKC3000D4096G NVME SSD drive, even when idle. Without load, it converges to 85-90 degrees Celsium. Laptop is indeed very hot at that and the fan is running all the time. The problem is reproducible when booting in single-user mode. System is Debian running kernel 6.12.12+bpo-amd64 (or 6.1.0-31-amd64 - the same result). However, when booting Linux Mint or Debian **LiveCD** (with similar kernel, e.g. 6.8; actually a USB flash drive, not CD), the drive does **not heat up** when idle, even if something is mounted from it. Only actively reading to it or writing to it makes the temperature climb. It stays hot even when doing echo s2idle > /sys/power/mem_sleep echo mem > /sys/power/sleep , but cools down when doing echo deep > /sys/power/mem_sleep echo mem > /sys/power/sleep How do I debug this? I tried experimenting with applying powertop suggestions, with using nvme_core.default_ps_max_latency_us=0 or (=20). Maybe there is some arcane nvme set-feature command to help? Maybe there is a way to temporarily suspend the device besides full s2ram (like hdparm -y, but for NVMe)? --- nvme get-feature /dev/nvme0 -f 0x0c -H shows a couple of non-zero entries (100 ms, 4). Entries seem to stay the same. --- # Update: partial workaround Based on [this bug report](https://bugs.launchpad.net/ubuntu/+source/nvme-cli/+bug/2064042) , I tried using nobarrier and it indeed stopped the heating (after s2ram cycle). Doing mount -o remount,barrier / immediately starts the power drain.