Did you try what I said to?If I dont do that before I begin to play all I do is studder with everything on low.I dont studder at all with that app going.You have to have witcher 3 open when you use the app so you can choose to limit it.
Try this app it worked for me with the studdering.Battle Encoder Shirase 1.6.2.Run it hit target choose witcher 3 and choose limit this.Go to controll to change how much cpu gets used..Play with the percent to see what works for you.
