trashopen up TF2 in windowed mode, keep task manager to the side as you play and have it sort by CPU usage (so the most usage is at the top)
whenever it stutters, you should end up seeing the process fucking shit up
I noticed that my CPU was working way too hard - 95-100% usage, along with 90-95% usage on my ram
Furthermore, my cpu was pretty hot- 53 C, which is super hot for what it normally is.