[SOLVED] Newly Built Computer Powering Off when Blender Benchmark Test is Run

[maquis]

This past week, I have been building/upgrading my computer to use for blender and UE5. After getting it booted up, I wanted to test it out by running the Blender Benchmark. While it seemed to be doing fine until that point, when I started running the Blender Benchmark using the CPU, it just shut off unexpectedly.

Stats on the computer:
power supply: corsair RM1000x (1000W) power supply (originally ran into this problem with a corsair 850W power supply, so switched it out, but still have the same problem).
motherboard: my old asrock b450m/ac -- have updated the bios to 2.70 to see if that helped
cpu: ryzen 9 5950
gpu: gigabyte rtx 3080 ti gaming edition

The temperatures seem pretty reasonable. The highest I've seen the cpu go while testing is about 60C. I've checked them while trying to start the blender benchmark, and I don't see them go up in the half-second before it turns off. The power-down has happened within the first 2 minutes after booting up from being off overnight. The cpu has a corsair icue liquid cooling system, and the case has 5 fans currently with reasonable airflow direction (intakes at the front and side, outflow at the top and back). I have more fans on the way currently (corsair 5000d airflow case). I did turn off the overheating shutdown in my bios to ensure that it wasn't somehow causing the shutdown.

I have had the shutdown occur once when running the benchmark with the GPU, but the rest of the times I have tried, it has worked if run with GPU, but powers off if run with CPU.

What is the best way to diagnose what is causing the power-down? This is my first time building a pc instead of buying a pre-built one, but I'm not seeing where I have gone wrong. From what I can tell, the power supply should be big enough to support the cpu and gpu. All the calculators I've found suggest that for my CPU and GPU combination, a 700W power supply is sufficient.

I did see something online (https://blender.stackexchange.com/q...-my-computer-whenever-cycles-renders-anything) where someone said they solved a similar problem by changing a bios setting related to VRM usage shutdown, but I couldn't find any settings similar to what they explained in my BIOS.

I would appreciate any recommendations for where to look next!

 

[vMax]

Running Hardware Info should show you the VRM temps to rule that out.

Motherboard is not the greatest, especially on the VRM side for such a strong top end CPU, especially under a sustained all core load like blender. All the other parts are very good including the case, PSU, stellar GPU. No doubt you will upgrade the motherboard at some point to a B550 for the better VRM and PCIe Gen 4.

Hopefully someone with a lot more knowledge on the AMD side and or with this motherboard will jump in with suggestions.