System:

• Asrock x399 Fatal1ty
• Threadripper 1900x
• 64GB DDR4 3600 (running at 3000)
• 3090/3070 ti
• Corsair RM1000x

Put together a system from some older threadripper parts I had and it's been running fine for a few months now on an old RM850x (2018 model). It runs fine, but it was getting too close to the rated wattage of the 850 if I left the GPUs uncapped.

So I ordered/installed a RM1000x (ATX 3.1 PCIe 5.1). System powered up for 30 sec, powered off., then back on again, repeat. No video output/POST. Reinstalled RM850x, worked fine. So I sent the RM1000x back to amazon and waited for the replacement. (I did some more troubleshooting but that's the gist of it.)

New RM1000x arrives. Same issue. Reinstall RM850x, works fine. Install different RM850x along with its cables, also works fine. Reinstall RM1000x, restarts every 30 sec, no video out.

I doubt that I got 2 defective RM1000x, but I also doubt that I somehow installed both of them wrong multiple times while being able to install the 850s just fine. Not really sure what's going on here.

I verified that the 850 and 1000 share the same cable type (type 4) and tried the 850 with the 1000 cables and the 1000 with the 850 cables.

• RM1000x with RM1000x cables = Restart every 30 sec.
• RM1000x with RM850x cables = Restart every 30 sec.
• Both of the RM850x with RM1000x cables = Restart every 30 sec.
• Both of the RM850x with RM850x cables = works fine.

Going to try the RM1000x in another system (AM4) tomorrow, and call Corsair to see what they say. Just wanted to put this out there and see what everyone thought. Never had power supply swap not "just work" before.