best CPU stress testing tool ?

SIdenote on the 26.6 of P95 vs. others....

I was experimenting with Prime 95 old (26.6) vs newer, (v28.1), on my 7700K with Noctua NH-D15, and got 68C and 76C, respectively....; although 8C higher temp is noticeable, it is hardly an instant overheat condition either, IMO....(perhaps the 8700K is affected more adversely?)