In the old days of PC gaming stuttering was usually sound related believe it or not. It can still affect modern gaming. Make sure you have up to date sound drivers and that you don't have too many sound devices active such as HDMI, optical, USB, analog, etc. Pick one output that works best with your set-up and disable the rest.
Me for example, I never install the HDMI drivers when installing Nvidia's driver package. I always unclick them as I never use HDMI sound. I drive external, powered desk top speakers using an AudioEngine DAC. I use USB sound out to drive my external DAC because my current motherboard doesn't have optical out. If it had optical out I would use that instead and have in the past. Optical out is always the best with an external speaker setup. I don't game with a headset. Every sound set up is different.