After digging through ACPI tables and WMI interfaces I managed to get full independent fan speed control working on the Alienware 16X Aurora on Arch Linux.
Dell hides fan control in a proprietary SSDT called AWCCTABL. By decompiling it with iasl and reverse engineering the WMAX ACPI method, I found the exact protocol.
CPU fan at 100%:
echo '\_SB.AMWW.WMAX 0 0x15 {0x02,0x32,0x64,0x00}' > /proc/acpi/call
GPU fan at 100%:
echo '\_SB.AMWW.WMAX 0 0x15 {0x02,0x33,0x64,0x00}' > /proc/acpi/call
Where the third byte is the speed from 0x00 (0%) to 0x64 (100%).
Thermal profiles also work:
echo '\_SB.AMWW.WMAX 0 0x15 {0x01,0xA0,0x00,0x00}' > /proc/acpi/call # Balanced
echo '\_SB.AMWW.WMAX 0 0x15 {0x01,0xA1,0x00,0x00}' > /proc/acpi/call # Performance
echo '\_SB.AMWW.WMAX 0 0x15 {0x01,0xA3,0x00,0x00}' > /proc/acpi/call # Quiet
echo '\_SB.AMWW.WMAX 0 0x15 {0x01,0xAB,0x00,0x00}' > /proc/acpi/call # Game Shift
Built a GTK4 GUI app with real working sliders on top of it. Full project with installation instructions on GitHub:
https://github.com/Hugo2049/alienware-16x-fan-control
The methodology should work on other Alienware models — the ACPI path and fan IDs might differ but the approach of dumping ACPI tables with acpidump and decompiling with iasl is the same.
Note: reverse engineering methodology worked out with assistance from Claude (Anthropic).