Device shutting down and power cycling again
Device shutting down and power cycling again
There's a good chance it's the PSU. 750W seems a little low for that build IMO Easy way to test is to reduce the power limit in something like MSI afterburner. Set it to about 80% and see if the problem persists. If it works fine then it's most likely a PSU issue. The good news is you can run this until you can get yourself a new PSU! Just be sure to reset the power limit when you install it =P I'd recommend a 1000w unit from a good brand. It's probably a little overkill but a good PSU should last for years, even with more powerful GPU's!
This seems related to power supply concerns. I believe the issue isn't a lack of wattage, but rather how it's being delivered. I tested with a 9900k and a 3090 on an 850W PSU—do you have separate PCI-E cables for the GPU or are you using internal connectors? You should use individual wires for each required pin. Also, confirm the CPU power cables are connected to the motherboard properly.
Did you verify the temperatures? The cooler wasn't mentioned. Also, have you run the newest bios?
I've connected all the CPU power to the motherboard. Regarding your question, comparing a pig tail cable to two separate ones depends on your setup and needs. You mentioned using it with a 3070 and a 3700X, which worked well, so it seems fine for you. Your power draw stays within the PSU's limits, indicating sufficient headroom. No need to worry unless you're planning more components.
I own a lian li galahad 240 aio cooler, and the temperatures looked normal during checks, reaching about 75°F under load. The BIOS is pretty old—version 2607, which is the lowest required for the 5000 series.