Brazilian modders at TecLab have built an Nvidia RTX 5090 using three conventional 8-pin power connectors instead of the troublesome 16-pin design.
Reports of melting 16-pin connectors have followed Nvidia’s RTX 40 and RTX 50 cards, with similar damage appearing on AMD RX 9000 boards using the connector. The newer 12V-2×6 standard was supposed to improve power balancing and protection compared with 12VHPWR, but reports of overheated connectors have continued.
GPU and power supply makers have produced specialised cables intended to reduce the risk, but without completely eliminating the problem.
TecLab decided on the less diplomatic approach of getting rid of the 16-pin connectors. The team modified a custom Galax HOF OC LAB RTX 5090, which normally carries two 16-pin power sockets, and replaced them with three Mini-Fit Jr 8-pin connectors. It follows an earlier TecLab experiment using XT90 connectors capable of handling currents of up to 90A each.
For the latest version, the modders returned to familiar PC hardware and demonstrated that conventional 8-pin connectors could drive the card without BIOS or software changes.
TecLab rewired the Sense 0 and Sense 1 pins so the RTX 5090 would recognise the altered power arrangement and permit its maximum available power. The connectors were installed on the back of the PCB using copper plates wrapped around the cable ends. A total of 24 heavy-gauge wires then carried power from the connectors to the supply points on the front of the PCB.
The finished arrangement used nine +12V lines, with each carrying roughly 8-8.5A.
TecLab gradually increased the card’s power from 400W through 500W and 600W before eventually reaching 900W through the three 8-pin connectors. Temperatures and voltages were monitored throughout the torture session.
The PCIe specification rates a standard 8-pin GPU connector at 150W, although that figure is a defined operating limit rather than the point at which the hardware instantly turns into molten plastic. During testing, the RTX 5090 drew peak currents above 60A and reached 3400MHz.
TecLab said the wiring and solder joints handled the beyond-specification load while remaining within its measured electrical and thermal limits. The modders then pushed the arrangement beyond 120A at roughly 3400MHz for more than an hour. Cable temperatures reportedly remained around 35C during that test. TecLab removed the third connector and repeated the exercise with two 8-pin plugs. The card continued drawing more than 66A while operating above 3200MHz, with infrared measurements reportedly staying below 25C.
Things became sillier when TecLab disconnected another plug and ran the RTX 5090 from a single 8-pin connector. The card maintained about 65A while running between 3.1GHz and 3.2GHz. The single connector reached roughly 45C during the stress test, while the hottest part of the cable reached about 65C.
Those figures are far beyond the normal 150W rating associated with an 8-pin PCIe connector, so this is an engineering demonstration rather than something owners should try with a soldering iron after lunch.
TecLab reckons the experiment shows the older connector design can still deliver serious current when the wiring, contacts, and PCB connections are built appropriately. Whether graphics card makers would consider returning to multiple 8-pin sockets is another matter. The industry has already sunk plenty of effort into the 16-pin ecosystem and 12V-2×6.
