The Sys Management Bus (SMBus) is a serial interface for managing devices such as voltage and temperature sensors, fan controllers, and power regulators. It's also the protocol used by the low-speed PCI Express bus in AMD K10 and later processors. The SMBus is defined by Intel: you can find the full documentation here.


When the chipset is equipped with SMBus, it embeds a dedicated subsystem called ACPI, which allows BIOS, OS, and other peripherals to communicate with devices on the SMBus. This communication can be used by OS or any other application to monitor temperatures, voltages of sensors, adjust fan speeds … even overclock!


Downloading drivers for your computer or laptop from the manufacturer's official site in the list of available drivers you can find a certain driver with the name AMD SMBus.


Sometimes when you install Windows the system installs this driver itself if it is in the standard package. If you see an unknown SMBus device in Task Manager, you have to install the driver manually.


What is AMD SMBus?

The AMD brand name is the name of the manufacturer. And SMBus is a computer bus that manages system management. The goal of this bus is to allow various devices connected to the PC to be controlled directly instead of via individual signals. The SMBus from AMD may also be used to query device status and access device properties.


Some of the available functions are:

  • Computers can read temperature values or fan speed.
  • The bus allows devices to be added, removed, and interrogated.
  • The computer will receive messages from devices on the SMBus.
  • It is possible to control a device's functionality on the SMBus by reading and writing DIO ports.


Thus we can conclude that the AMD SMBus driver is a mandatory driver which must be installed on your computer if you have the corresponding device in the Device Manager or if the official site of your notebook or motherboard manufacturer has this driver available for download.


If you don't have this driver installed on your Windows, the computer will warn you about it with yellow exclamation marks.