The noise can be many things, a coil-whine for example, which is very annoying but not necessary a sign of failing hardware. Do you have a USB stick or a spare hard drive you could boot up a clean OS from? Perhaps you have a virus or something which is eating up resources. If you could test performance that way, you could be sure it's your hardware and not something about your OS. I'm asking because I was fixing a machine a few months ago which was only throttling and going 100% full load when it was not monitored (the task manager was not running for example). The GPU and the CPU was running 100% all the time except when I started something to check it. I was lucky that the GPU had a coil whine under load and I got suspicious about the poor performance, and started monitoring temps. But soon as I started task manager the CPU was idling at 0%. Luckily I also installed Speedfan for some reason and that showed me 100% load when I closed other things (e.g.: resource monitor/task manager). So checking you hardware with a clean boot could prove helpful perhaps.