I know everyone says to keep the CPU processing long term at 100% does damage, but what about 50%?
Anyone have an explanation based on facts about electronics?
Im 99% no, based off my experience w/ countless computer systems ... the CPU is often times the longest lasting component in a system.
2 things you can do to make sure it lasts its designed lifetime:
1. Make sure heat is under control(temperatures are within spec).
2. More importantly, make sure the voltages are within spec.
Even overclocking will not diminish a CPU's lifespan if its done properly.
Example would be undervolting & overclocking.
Furthermore, running a CPU @ 100% usage 24/7 ... make sure its temps are definitely within spec during that time ... most CPU's dont run 24/7 so its easy to not pay attention to their 100% usage temperature.
While 100% usage will not wear on a CPU ... the power delivery section on the motherboard will be under substantial stress the entire time and this is what sees the most wear. Proper cooling is usually an afterthought on these areas on many budget/mainstream consumer motherboards.