The missing Linux view
Astral Pins is a GTK4 monitor for the six power pins on ASUS ROG Astral RTX 50-series cards. It reads the onboard ITE IT8915FN monitoring chip and shows per-pin voltage and current, a two-minute history, and status.
ASUS exposes this telemetry through GPU Tweak on Windows. Linux had nothing. The tool uses read-only chip access and no kernel driver. Project source and hardware scope.
Register map and transfer method
The register map puts the chip at 0x2b, with 24 bytes from 0x80. Six pins, each with two bytes of millivolts and two bytes of milliamps. Values are big-endian and the pin order is reversed.
Raw I2C_RDWR transfers through the NVIDIA adapter returned values that did not decode. The kernel’s SMBus read-byte-data interface works. Each poll does 24 register reads through ioctl.
The address and register offsets were correct from the start. Only the transfer method had to change. Implementation.
Stale and missing readings
The interface keeps two minutes of history. When a sensor read fails, the live values become dashes and the plot is labelled historical. Other GPU telemetry keeps updating.
Threshold checks use sustained current, so one high sample does not trip them. The tool also flags a near-zero pin while the connector is under load.
A horizontal current guide on the graph gives a per-pin summary of the highest visible reading at or above that level. Missing history stays distinguishable from a low value. Graph interaction change.
Installation
One dependency manifest covers Debian/Ubuntu, Fedora/RHEL, Arch, and openSUSE. The installer checks for a working NVIDIA driver, then installs desktop dependencies and launchers. It does not touch the GPU driver.
Setup has dry-run and hardware-free preview modes, plus checks against distribution packages. Linux setup and dependency maintenance.
Evidence and limits
The register layout came from one card. Other Astral models may differ. The tests use simulated readings and cover interface and threshold behavior.