Question PC Randomly Shutting Down & Rebooting

[MrGrumpsy]

Hey everyone,

I built my PC back in February, and everything was running smoothly until a few weeks ago. Out of nowhere, it started randomly shutting down and immediately rebooting. This usually happens under load (like gaming), but I’ve also experienced it once or twice while idle on the Windows desktop.

The behavior is inconsistent:

• Sometimes I can game for two hours before it crashes
• Other times, it restarts within minutes of launching a game

What I’ve Tried So Far (No Success):

• Updated BIOS
• Updated all drivers
• Clean install of NVIDIA drivers (not using DDU)
• Disabled EXPO profile
• Tried undervolting the GPU and reverting to default settings — no change
• Tried with different 12vhpwr cables; MSI GPU came with one (3 to 1 split); the one from the Corsair PSU (2 to 1 spit)
• Checked for visual damage on 12vhpwr cables and re-seated them

Temperatures & Power Info:

• GPU Temp: Stays under 65°C
• CPU Temp: Stays under 50°C
• PCIe 12V Rail: (checked via HWInfo): Never drops below 12V

PCPartPicker Part List
CPU: AMD Ryzen 5 7600X3D 4.1 GHz 6-Core Processor
CPU Cooler: Thermalright Peerless Assassin 120 SE 66.17 CFM CPU Cooler (€45.89 @ Proshop)
Motherboard: Asus ROG STRIX B650E-I GAMING WIFI Mini ITX AM5 Motherboard (€256.89 @ Proshop)
Memory: G.Skill Flare X5 64 GB (2 x 32 GB) DDR5-6000 CL30 Memory (€212.63 @ Proshop)
Storage: Lexar NM790 4 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive (€269.17 @ Proshop)
Video Card: MSI VENTUS 3X OC PLUS GeForce RTX 5080 16 GB Video Card (€1459.00 @ Alza)
Power Supply: Corsair SF850 (2024) 850 W 80+ Platinum Certified Fully Modular SFX Power Supply (€197.57 @ Proshop)

I read that the RTX 5080 might have issues with sudden power spikes, where it briefly draws significantly more power. Could it be that my Platinum-rated power supply is shutting down the system in response to that?

Any ideas what might be causing this? I'm running out of options and would really appreciate any insight, especially from anyone who's run into something similar.

Thanks in advance!

 

[Lutfij]

Welcome to the forums, newcomer!

Updated BIOS
For the sake of relevance, please state the BIOS version.

Clean install of NVIDIA drivers (not using DDU)
You're advised to use DDU in Safe Mode to remove all GPU drivers(intel, AMD and Nvidia), then manually install the latest GPU driver sourced from Nvidia's support site, in an elevated command, i.e, Right click installer>Run as Administrator. I would also disable the iGPU in BIOS prior to running DDU.

Might want to also see if you can source another PSU that's reliably built with more power than your entire system needs, to rule out the PSU being overwhelmed.

Reboots when the system is taxed can happen for two reasons;
1| An overheating issue
2| Your PSU is incapable of delivering power when taxed

 

[MrGrumpsy]

Welcome to the forums, newcomer!

Updated BIOS
For the sake of relevance, please state the BIOS version.

Clean install of NVIDIA drivers (not using DDU)
You're advised to use DDU in Safe Mode to remove all GPU drivers(intel, AMD and Nvidia), then manually install the latest GPU driver sourced from Nvidia's support site, in an elevated command, i.e, Right click installer>Run as Administrator. I would also disable the iGPU in BIOS prior to running DDU.

Might want to also see if you can source another PSU that's reliably built with more power than your entire system needs, to rule out the PSU being overwhelmed.

Reboots when the system is taxed can happen for two reasons;
1| An overheating issue
2| Your PSU is incapable of delivering power when taxed

Thanks for the fast reply.

I updated to the latest Bios version ( Version 3222 ) from the official rog.asus site

I am currently not at home for testing the driver reinstall with DDU, will answer back asap. If this does not help i will look into getting a 1000W PSU for testing.