I currently have a Corsair RMe 650W 80 Plus Gold power supply and want to upgrade to a Corsair RM850x fully modular ATX 3.1 model with PCIe 5.1 support. Can I unplug the existing PSU and connect the new one using the cables already installed, or do I need to replace every cable with the ones included with the new power supply?
3 Answers
There may be an exception here if both exact units use the same Corsair cable type, such as Type 4, but you need to verify the specific model and cable labels first. Don’t rely on the brand alone. If there’s any uncertainty, replace the cables with the ones supplied with the RM850x.
The safest rule is to use the cables that came with the replacement PSU. Modular cables are not universally interchangeable, even between different models from the same brand, because the PSU-side pinouts can differ.
Check the cable type printed near the PSU-side connectors and compare it with Corsair’s compatibility and pinout information. The newer ATX 3.1 unit may also include a newer 12V-2x6 GPU cable, so use that cable for a compatible graphics card rather than reusing an older high-power GPU lead.

That makes sense. I’m still learning, so I’ll check the exact cable type and probably redo the cable management while swapping in the new PSU.