Custom RTX 5090 mod uses a power distributor to reduce 12VHPWR heat

A custom solution for connector heat

Reddit user u/DallasGrave shared a modification for an RTX 5090 featuring a module attached to the back of the graphics card. According to the user, the custom-made device is a power distributor that splits the current load across more wires to lower temperatures at the 12VHPWR connector.

The user is apparently connected to GRAVEPC.com, a company that mainly offers custom cooling solutions for small form-factor PCs. He said GRAVEPC is a PNY partner and that a PNY-specific card with a similar modification could be purchased directly from the company with a full warranty. The modification is not currently listed on its website, and the warranty claim is uncertain because PNY has not consistently honored warranties for the 12VHPWR issue involving third-party cables.

Why the connector can overheat

The 16-pin connector used by many Nvidia graphics cards carries high current through what is essentially a 12-pin power connector. Four smaller pins are sensors, while the remaining 12 are divided between six +12V and ground connections. It typically uses 16AWG cables that are theoretically capable of handling up to 600W.

Poor contact between pins can create high resistance, leading to heat buildup. Uneven current distribution can also contribute to overheating. Older multi-8-pin connector arrangements had greater safety margins, but newer graphics cards draw more current, and Nvidia chose to route that power through fewer wires.

How the RTX 5090 modification works

The modification adds connections soldered directly to the RTX 5090's power rails on the PCB. Those wires route to a separate distributor board containing two female 8-pin connectors. The housing appears to have been resin-printed and designed for the specific graphics card.

It is unknown whether u/DallasGrave designed the distributor himself or whether it includes additional power-delivery or protection components such as capacitors and fuses. During his stress test, he ran the card at full load while pulling 550W for 48 hours. He reported that the joint never exceeded 40°C during the test.

Although the solution appears cleaner than other power modifications, it remains invasive because its wiring must be soldered directly to the card's power rails.