Enthusiasts from the TecLab YouTube channel have assembled the world’s first GeForce RTX 5090, which is powered exclusively by classic 8-pin PCIe connectors.
The card not only managed to run, it also withstood a load that was unthinkable for the official specifications of the old connector.
The basis of the experiment was the Galax GeForce RTX 5090D HOF OC LAB XOC, a top version with massive cooling and two 16-pin connectors. The modders completely disassembled the video card and removed both 12V-2×6 connectors, leaving a bare PCB.
https://www.youtube.com/watch?v=Y2RJcy5LwOk
Three 8-pin connectors were installed on the back of the board, each of which was soldered directly to the power circuits with thick, large-section wires. Separately, we had to reconnect the sense pins so that the card would not run into software power limitations. To remove heat, a liquid cooling system with a full-size water block was used.
Officially, one 8-pin connector is rated at 150 W, although its actual headroom is noticeably higher. During the hour-long stream, the load was increased gradually, starting from 400 W and reaching 900 W on three cables.
At its peak, the modified RTX 5090 consumed more than 120 A, and the GPU frequency reached 3400 MHz. At the same time, there were no interventions in the BIOS or software modifications; all changes concerned only the hardware.
Next, enthusiasts checked how the card behaved when some of the cables were disconnected:
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two 8-pin connectors – the current dropped to 66 A, frequencies remained at 3200 MHz
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one 8-pin connector – 65 A and 3100 MHz
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three 8-pin connectors – more than 120 A and peak 3400 MHz
The drop in performance when switching to one cable turned out to be minimal, which indicates a serious margin of safety of the old standard. Although this mode of operation goes far beyond the scope of any certifications and cannot be called safe.
The PCI-SIG organization has already revised the design of the 16-pin connector, releasing a revision 12V-2×6 with improved contact and a more secure fit. Despite this, reports of melted connectors continue to appear, and the problem affects not only Nvidia RTX 50 and RTX 40, but also certain AMD Radeon models with the same connector.
TecLab’s experiment shows that the time-tested 8-pin is still capable of serving flagship video cards, albeit at the cost of more cables and board space. The question is whether manufacturers are ready to return to a bulky but predictable solution instead of a compact 12V-2×6.
