I recently replaced just about every component on my desktop computer:
CPU (AMD FX 8350 8-core processor)
Heat sink fan (because the one that came with the CPU was frickin loud)
16 GB RAM (8GB x 2)
Video card (MSI GeForce GTX 970)
I read that a computer shutting off suddenly can be related to components overheating, so I downloaded HWMonitor (a program that monitors your hardware and gives info like temperatures and fan RPMs). I do not see any unusual heat readings when the computer is running normally (e.g. browsing the web, running programs on the desktop). The problem usually occurs when I launch a game; so far it has happened with Assassin's Creed Unity and Far Cry 4.
I have not been able to get an accurate heat reading for other, less intense games that require fewer system resources, but I suspect the problem may actually lie in my PSU, which has a max output of 480W. I've used multiple online "power supply calculators" to see what they recommend given my setup. Every single one I've tried has given me different results for various reasons. For example, one tells me I would only need an output of 400W while another says I need over 500W. The one that I trust most is Newegg's, which tells me I need at least 1200W output.
I'm still kinda new to upgrading computers, so I'm wondering if someone with more knowledge about hardware can diagnose this problem. Let me know if you need more details on my configuration.
TL;DR is it time for a new power supply?