M.2 NVMe easily overheats under sustained intensive use[1] and throttles down, and may persist throttled even after cooling down. If an idle system runs M.2 hot, there is not a lot of margin for heavy use of the M.2 NVMe.
When running ClearLinux, the temperatures reported by my idle unformatted Samsung M.2 NVMe approach 60C, while the CPU temperature is at 51C.
This is not a hardware issue. The same hardware configuration, with Fedora 32, the M.2 memory idles at around 39C.
What could be the cause of high temperatures at the idle NVMe?
Note[1]: To see this, run a read/write benchmark like in gnome-disks with settings that keep it running for 15 minutes or however long for the temperature to approach its threshold.
uptime and sensors output follows.
$ uptime; sensors
23:09:02 up 4 days 19:34, 2 users, load average: 0.08, 0.09, 0.09
iwlwifi_1-virtual-0
Adapter: Virtual device
temp1: +49.0°C
acpitz-acpi-0
Adapter: ACPI interface
temp1: +27.8°C (crit = +119.0°C)
nvme-pci-0100
Adapter: PCI adapter
Composite: +56.9°C (low = -273.1°C, high = +84.8°C)
(crit = +84.8°C)
Sensor 1: +56.9°C (low = -273.1°C, high = +65261.8°C)
Sensor 2: +60.9°C (low = -273.1°C, high = +65261.8°C)
pch_cannonlake-virtual-0
Adapter: Virtual device
temp1: +53.0°C
coretemp-isa-0000
Adapter: ISA adapter
Package id 0: +51.0°C (high = +86.0°C, crit = +100.0°C)
Core 0: +50.0°C (high = +86.0°C, crit = +100.0°C)
Core 1: +50.0°C (high = +86.0°C, crit = +100.0°C)
Core 2: +51.0°C (high = +86.0°C, crit = +100.0°C)
Core 3: +50.0°C (high = +86.0°C, crit = +100.0°C)
Core 4: +50.0°C (high = +86.0°C, crit = +100.0°C)
Core 5: +50.0°C (high = +86.0°C, crit = +100.0°C)
Core 6: +51.0°C (high = +86.0°C, crit = +100.0°C)
Core 7: +50.0°C (high = +86.0°C, crit = +100.0°C)