No, a CPU cannot downclock itself. It relies on external software or BIOS settings to adjust its clock speed.
No, a CPU cannot downclock itself. It relies on external software or BIOS settings to adjust its clock speed.
As the others have said, thermal throttle. Good chance with something that age the thermal paste is at end of life. If you are comfortable working on the PC, grab a new tube/pack from the store and replace the current paste. (ensure you clean it properly before putting on the new paste) There is also a chance your cooling AIO or Tower could be at end of life as well. After the paste is replaced, if you are still having throttling, then its the cooling. a few ways to verify this though, is to get a program like Furmark (free) and run the CPU burner test and see what happens with the results. If its throttling excessively during the test then you know its time for some maintenance.
Retrieve HWInfo to view CPU temperature readings during throttling.