So, here are my setup details. I bought everything new, except my graphic card and sound card, which were pulled from my old system. ASUS PRIME B350-PLUS ATX Motherboard AMD Ryzen™ 5 1400 Quad Core CPU Noctua NH-D15 CPU Cooler (using AM$ bracket kit) 8GB (2x4GB) Corsair Vengeance LPX 2400MHz DDR4 RAM Radeon RX480 Nitro+ 4GB GPU 750W Corsair TX750M 80+ Gold Semi Modular PSU 2 x 525GB Crucial MX300 SSDs Archer T6E - AC1300 Wireless Dual Band PCI WiFi card SoundBlaster Z Soundcard Phanteks Eclipse P400 Windowed RGB Mid Tower Case 3 x Arctic F12 120mm Temperature Controlled PWM Case Fans So, first, a little bit about how the system is setup. I was not able to fit both CPU cooler fans into my rig, due to memory module size; the heatsinks on them are too big, so I have 1 fan placed between the two cooler blocks. The fan that is being used is not PWM, as it only uses 3 pins. Due to this, I had to set BIOS to ignore the fan and set the minimum RPM to 600 (the highest number available). I then set the profile to Turbo. I have my memory modules set to the XMP profile for 2400Mhz, by allowing DOCP. They are in the 2nd and 4th slot. I have updated to the latest BIOS available and installed all the drivers from the manufacturer's motherboard website. I have the latest Crimson drivers available installed for my GPU. The PCI Wifi card is installed, with latest drivers. My sound card is fully installed, with the latest drivers. I have Windows 10 installed on one of the SSDs, and use the other SSD to install games. So, when I use my PC, everything works fine, until I try to run a graphically demanding game (Rise Of The Tomb Raider, for instance). The games I play all seem to run on ultra settings quite happily, until about a quarter of an hour later, when my PC freezes. It doesn't reboot, and there is no response from any input. The only option is to hold the power button on my PC, until it turns off. I've tried various configures for the BIOS and GPU, but to no avail. If anybody on here has any suggestions for a fix, I would be greatly appreciative. Thankyou.