radeontool

radeontool [ -h ] [ -b [on|off|] ] [ -d [on|off] ] [ -f [on|off|] ] [ -g [red|green|blue] [] ] [ -i ] [ -l ] [ -S ] [ -q ] [ -r [] ] [ -t [on|off|pal|ntsc] ] [ -v ] [ -X ] [ -x ] [ -M ] [ -C ] [ -O ]

-h
    Displays a help message and exits.

-b [on|off|]
    Controls laptop panel backlight. 'on' for full brightness, 'off' for disabled, or a specific brightness '' (0-255).

-d [on|off]
    Enables or disables digital outputs (DVI/HDMI).

-f [on|off|]
    Controls the fan speed. 'on' for full speed, 'off' for lowest, or '' (0-255 or 0-100%) for specific speed. Note: some cards have limited support.

-g [red|green|blue] []
    Sets or reads the gamma value for a specified color channel (red, green, blue). If is omitted, it reads the current value. Defaults to all channels.

-i
    Prints various card information, including PCI ID, chip ID, and memory size.

-l
    Lists all supported features and their current status.

-S
    Saves the current card state to a configuration file.

-q
    Queries and displays the current status of various features like backlight, DVI output, and fan.

-r []
    Reads from or writes to a specific Radeon register. and should be hexadecimal. Use with extreme caution as this can damage hardware.

-t [on|off|pal|ntsc]
    Controls the TV output, allowing to turn it on/off or set PAL/NTSC mode.

-v
    Enables verbose output for more detailed information.

-X
    Enables XFree86 DGA (Direct Graphics Access) functionality (experimental).

-x
    Disables XFree86 DGA functionality.

-M
    (Experimental) Sets the memory clock speed in MHz. Use with extreme caution; can damage hardware.

-C
    (Experimental) Sets the core clock speed in MHz. Use with extreme caution; can damage hardware.

-O
    (Experimental) Resets clock speeds to their default values. Use with caution.

radeontool is a command-line utility designed to control various features of ATI Radeon graphics cards under Linux. It provides direct access to hardware-specific settings, allowing users to manage aspects such as laptop panel backlight, digital output (DVI/HDMI) enable/disable, and fan speed control. It can also be used to adjust gamma settings, access the DDC bus (I2C), and dump or write to Radeon registers (with extreme caution).

Additionally, radeontool offers experimental features like controlling TV output, enabling/disabling XFree86 DGA access, and highly experimental overclocking capabilities for memory and core clocks. Due to its direct hardware interaction, particularly with overclocking and register manipulation, users are advised to exercise caution as improper use may lead to hardware damage or instability. It is a powerful tool for low-level Radeon management.

radeontool is explicitly labeled as a highly experimental utility. Its functionality may not work on all ATI Radeon cards, and many features, particularly overclocking and direct register manipulation (using -r), carry a significant risk of causing permanent hardware damage or system instability if used improperly. Users should proceed with extreme caution. It typically requires root privileges or appropriate permissions to access device files like /dev/mem and /dev/pci.

For most operations, radeontool requires direct access to system memory and PCI devices, typically necessitating root privileges or specific user permissions granted to access files like /dev/mem and /dev/pci.

The command returns an exit status of 0 upon successful execution, and a non-zero value (greater than 0) if an error occurred during operation.

As noted in its documentation, radeontool is experimental, and certain features may not function correctly on all Radeon card models. Overclocking functionality is particularly prone to issues and can lead to hardware damage.

radeontool was authored by David Airlie and is based on work by others. Its development is rooted in providing a low-level command-line interface for managing ATI Radeon graphics card features, often interacting directly with the hardware through kernel interfaces. Its existence reflects the need for fine-grained control over graphics card settings, particularly for older or specific Radeon chipsets under Linux.

xrandr(1), atitvout(1)