12VHPWR Guard: A Tool to Prevent Overheating on Nvidia RTX 5090 Graphics Cards

Nvidia RTX 5090 users have been plagued by concerns about the safety of their graphics cards due to overheating issues caused by the 12V-2×6 cable. To mitigate this risk, a user has developed a tool called 12VHPWR Guard that detects current imbalances on the potentially troublesome cable.

The tool uses per-pin sensing, which is mainly available on premium cards such as Asus' ROG Astral series. It reads the ITE IT8915FN monitoring chip installed on supported ROG Astral cards over the GPU's I2C bus through NVAPI, with HWiNFO shared memory available as a fallback.

The developer claims that 12VHPWR Guard was validated against HWiNFO and found that per-pin readings agreed within 0.02A at idle and under ~500W gaming load.