Nvidia Kept Per-Chip VRAM Thermals Hidden, Modders Unlocked Them

Modern Nvidia graphics cards equipped with GDDR6, GDDR6X, and GDDR7 memory can report temperatures for each physical memory chip individually, even though the feature was never officially documented. A team of hardware modders and utility developers uncovered the telemetry by analyzing the GPU's memory-mapped I/O (MMIO) registers.

Standard diagnostic tools like GPU-Z have historically displayed only a single figure for video memory thermals. As the developers discovered, that reading was never an average across the board; it simply mirrored the single hottest module at any given moment.

Access to individual sensors revealed substantial thermal variance across a single board. Testing on a GeForce RTX 3080 showed one memory chip reaching 86 °C while surrounding chips stayed significantly cooler. That granular data provides a direct way to pinpoint uneven mounting pressure, degraded thermal pads, or poor contact with aftermarket waterblocks.

The feature was unlocked through collaboration among Brazilian modder Paulo Gomes, MSI Afterburner creator Alexey Nicolaychuk (known as Unwinder), and HWiNFO author Martin Malik. Per-module readouts have been incorporated into experimental builds of HWiNFO and made accessible in MSI Afterburner via a Hotspot.dll plugin.

Following the initial release, the team confirmed that the same MMIO registers expose individual chip temperatures on GeForce RTX 50 series cards, showing that Blackwell maintains the hidden per-module telemetry.

Source: habr

Via: VideoCardz