Hello, I've been having this same problem since I made my PC from scratch. It's whenever I play Grand Theft Auto V or Tom Clancy's Division I'll lag hardcore out of knowhere and have horrible rendering. This will last for 10 minutes before It'll go away for.. awhile. Here's what I've tried.. off the top of my head for both games;
Disabling Overlay (Steam/U-Play/GeForce The Expierence)
Re-installing all drivers
Re-installing Windows 10
Cleaning my computer (internal)
Checked my specs
Lowered settings (including advanced graphics)
Reached out for help over the year.. nothing helped.
The only thing I can think of that I haven't done is using the Razor program to shut off uneccesary programs.