Question New system reboots while playing demanding game

Oct 6, 2020
I built a new gaming computer a week ago, it didn't work on first boot up and the motherboard LED error showed that the DRAM was at fault so I re-seated the RAM sticks and it booted up fine. Then when I was playing a few games they where crashing with an out of memory exception and the recommended solution was to set up an automatic pagefile on my M.2 SSD which worked. However when I play my most demanding game Star Citizen, my computer will reboot at random, I've been able to play for hours and it wouldn't have any problems and sometimes it will reboot after just a few minutes of playing. It has also rebooted once during a torture test but it was a thermal shutdown from being at 115c for too long

Originally I thought it was a thermal reboot and in the Prime95 torture test the CPU was hitting 105-115c. I've reapplied thermal paste twice now and I'm only seeing 95-98c in the torture test and 90c in Aida64 system stability test. However I know its not a thermal reboot as I recorded the temps and usage on my second screen at the point of the reboot, the CPU was only running at 60% capacity and stayed at 70c while playing. The RAM was only seeing 85% usage, my GPU was at 100% usage but I have it thermally locked to 79c.

The system is not completely new, I'm using my old GPU, PSU and M.2 SSD and prior to the upgrade I was playing games just fine with those parts. I've also calculated my power supply requirement using the advanced OuterVision PSU calculator, its 480w and I have a 600w PSU. I'm not seeing any critical errors in the Windows logs and it takes longer to load after an auto reboot.

Are there any troubleshooting steps I can take to find out what might be causing the system reboots? I've tried the Windows Memory Diagnostic Tool and it didn't find any errors in the RAM. The last thing I'm willing to try is reinstalling Windows 10 as I have a lot of expensive licensed programs and some may need new licenses after that so I really need to try every other avenue before resorting to this.

Thank you in advance for your help and advice.

My specs
Motherboard: MSI MPG x570 Gaming Plus
CPU: Ryzen 5 3600XT 6C12T @4.25Ghz
CPU Cooler: Stock Wraith Spire with JetArt nano diamond thermal paste
RAM: Corsair Vengeance 2x 8GB DDR4 3200Mhz with XMP enabled
GPU: Nvidia GTX 970
PSU: CoolerMaster B600 ver.2 600w
SSD: Samsung Evo 970 M.2 NVMe 500GB
Case: Corsair Carbide Spec-Omega with 5 120mm fans, 2 intake and 3 exhaust
OS: Windows 10 Pro


Most reviews i see on the net say the CoolerMaster B600 ver.2 600w is a lower end PSU and being that it was released in 2015 its already 5 years old. Being that yours started out being mediocre and is getting long in the tooth, its time to replace it, even good PSU deteriorate over time.