No, PC Matic is designed to optimize your computer’s performance rather than hinder it. By providing routine maintenance such as cleaning out junk files, it keeps your computer running smoothly. If there is a slowdown during the scanning or optimization processes, it’s honestly outweighed by the benefits of keeping your system clean and optimized. That said, I didn’t experience any slowdowns in my tests anyway. However, if you’re looking for an antivirus with the lowest possible system impact you could try Bitdefender, which is fully cloud-based.