My RTX 3090 has been crashing during games, and I recently learned that using a daisy-chained PCIe power lead may contribute to instability. I currently have one GPU installed in a system with a Ryzen 7 5700X, ROG STRIX B450-F GAMING motherboard, 32 GB of RAM, Windows 11 Pro, and a Corsair RM850x power supply. Should I connect the card with two separate PCIe cables, and are there any specific replacement cables I need? I misplaced the cables that originally came with the power supply.
2 Answers
Use two separate PCIe power cables from the PSU to the graphics card rather than using both connectors on one daisy-chain cable. Since this is a modular Corsair PSU, use cables specifically compatible with the RM850x—ideally genuine Corsair replacement cables. Do not use modular cables from another brand or an unknown cable, because the PSU-side pinouts can differ and damage the hardware. An 850W RM850x is generally appropriate for a single RTX 3090, though power spikes can still expose a weak or failing PSU.
The safest choice is the PCIe cables that came with the RM850x. If they are lost, order the correct Corsair replacement cables for that exact PSU model and revision. Connect one cable to each GPU power socket, leaving the unused pigtail connectors hanging free instead of using them for the second connection.
I only have one GPU installed now; the older hardware list mentioned a possible second card. I’ll look for exact RM850x-compatible replacement cables rather than buying generic modular cables.