High-end Nvidia graphics cards, including the RTX 5090, have been documented to melt their power connectors when drawing very high wattage. Concerned about this happening to his own card, a PC gamer built a free, open-source application called "12VHPWR Guard" that monitors power draw and shuts the whole system down if it detects a dangerous sustained current on any pin. Wccftech identifies the creator by the Reddit username "CoolerThanNos," while Tom's Hardware names the developer as Humza Khalid, who built the tool with Claude AI.
The tool currently only works with ASUS' ROG Astral lineup of the RTX 5080 and RTX 5090, because those cards have per-pin current sensors that let the software monitor each of the six +12V pins individually. Tom's Hardware notes that the developer described this sensor feature as unique to the Astral cards, but points out that ASUS' ROG Matrix RTX 4090 and RTX 5090 also have per-pin sensors, and that the Matrix RTX 5090 is in fact listed as supported on the tool's GitHub page.
The software polls all six pins twice per second and forces a shutdown if any single pin draws more than 9.5A for 15 consecutive seconds. Both the amperage threshold and the time duration can be adjusted by the user, though the defaults were chosen deliberately so that normal power spikes or load swings don't trigger a false shutdown. For comparison, ASUS' own GPU Tweak III software issues a warning if a pin exceeds 9.2A, but according to the developer, that audible warning doesn't help if the user is deep in a game or away from the keyboard.
The application is lightweight, reportedly using about 35MB of memory and a very small amount of CPU time (Wccftech puts it at roughly 1% of a single core). It also includes fallback support for HWiNFO-based monitoring if it can't access the card's sensors directly, along with toast notifications, Windows Event Viewer logging, and detection for when sensor data is lost, so it doesn't falsely report that everything is fine. The code was reviewed by the developer and checked against two independent open-source implementations before being installed on his own system, and it currently supports Windows 10 and 11 with a Python 3.10 or higher requirement.
Tom's Hardware notes an irony in the tool's name: none of the supported cards actually use the original 12VHPWR connector, but rather the updated 12V-2x6 design, which adjusted connector dimensions to ensure fuller insertion. However, the underlying power wires and contact points are unchanged, so the melting risk remains. Given the high cost of these cards — Wccftech cites a $4,799.99 price for the RTX 5090 on Amazon, while Tom's Hardware notes the ROG Astral OC RTX 5080 starts around $1,810 — both outlets frame the tool as a low-cost safeguard, though it is not a substitute for making sure the power connector is properly and fully installed.