When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Include the age of the PSU apart from it's make and model. Include the version of your S, if you're on Windows 10. Include a screenshot of the structure for your disk partitions if you're working with a single HDD. Include a list of all the games and apps that you're taxing the system with(without stating an etc) in order for us to rule out other factors for causes of the stutter.
The issue could be a faulty or failing PSU, that your OS is corrupt, that the drivers might need a reinstall, that the OS might be having a memory leak or you need a BIOS update.