Corsair Power Supplies May Soon See Sensor Support Exposed Under Linux

Select high-end Corsair power supplies such as their RMi / HXi / AXi series are able to expose various sensor metrics via USB interface to the system. To date this sensor functionality has only worked under Windows with their proprietary software but now an open-source driver is seeking mainline inclusion for supporting these sensors under Linux.

Independent developer Wilken Gottwalt reverse-engineered the micro-controller found on the Corsair RMi/HXi/AXi power supplies and found it to be a proprietary but simple USB HID protocol. The controller exposes temperatures, current, and voltage levels along with other information like power uptime, power used, and power supply fan speed. This protocol on select models can also allow configuring the fan mode and mono/multi-rail voltage handling, and over-current protection.

With the Corsair-PSU driver patches posted on Sunday, however, it only exposes the sensor data under Linux but not configuring any of the tunables. The lack of configuration support is done for safety reasons due to the lack of documentation on this proprietary protocol and not wanting to damage any hardware.

Corsair refers to their proprietary software solution / protocol as Corsair LINK that spans from integrating power supply information to RAM, water cooling, and other Corsair products with various sensor and control knobs.

So for those with one of the high-end Corsair power supplies offering a USB interface for monitoring, this patch can allow basic monitoring of exposed sensors. All of the data is accessible via sysfs and jives with the HWMON subsystem. If all goes well we could see the new Corsair-PSU driver merged as soon as the Linux 5.11 kernel.