Fan Control

The fan is driven by the ICC's autoservo firmware - the kernel exposes a target SoC temperature and the firmware ramps the fan on its own to hold that temperature. There's no manual PWM/RPM control, just the target.

Kernel driver: drivers/ps5/fan/ (merged in ps5-linux-patches #25). Default target is 80°C.

Sysfs interface

/sys/bus/platform/devices/ps5-fan/target_temp

Read the current target:

cat /sys/bus/platform/devices/ps5-fan/target_temp

Set a lower target for more aggressive cooling (louder, but keeps the SoC cooler under load) - e.g. 65°C:

echo 65 | sudo tee /sys/bus/platform/devices/ps5-fan/target_temp

Valid range is 0-100 (°C). There's no need to slam it to a fixed "max" setting - the servo already ramps as needed once it has a target to chase, so just pick a target temp you're happy with.

Reported idle temps: default target (80°C) idles around 59°C SoC. Dropping target to ~40°C brings idle down to ~46°C, at the cost of constant audible fan noise ("jet mode"). Diminishing returns below that, the servo is already near its ramp ceiling.

ps5ctl

ps5ctl wraps this (plus LED, buzzer, and GPU clock) in a TUI/CLI/web control panel:

sudo ps5ctl --temp 65

or interactively via the Fan tab in sudo ps5ctl.

Standalone fan_mode kernel module

A separate, minimal alternative for benchmarking with the fan forced to a fixed EMC mode (auto/max/min) instead of a target temp, RE'd directly from the EMC ICC commands:

make -C /lib/modules/$(uname -r)/build M=$PWD obj-m=fan_mode.o modules

Force max speed:

sudo insmod fan_mode.ko zone=0 fan_mode=2 ; sudo rmmod fan_mode

Restore auto mode:

sudo insmod fan_mode.ko zone=0 fan_mode=1 ; sudo rmmod fan_mode

No adjustable percentage, the EMC only supports Auto/Max/Min modes. Max is loud, audibly described as "turbine mode" by testers.

No Dedicated GPU Temperature Sensor

There's no separate GPU-only temperature reading, only the combined APU die temp (Tctl), since CPU and GPU share one die:

cat /sys/class/hwmon/hwmon*/temp*_label   # find Tctl
cat /sys/class/hwmon/hwmon*/temp*_input   # value in millidegrees C

This has been a recurring question since early testing, there simply isn't a GPU-specific sensor exposed, Tctl is the closest available number and covers both.

Reference reading: GPU pinned at its floor (400MHz, /sys/class/devfreq/ps5-gpufreq/cur_freq), Tctl sat at 42.75°C. Normal CPU idle floor is ~798MHz, an active SSH session at sample time kept cores elevated (~1.6-3.2GHz spread) rather than fully idle.