I know this is a necro thread but: did the original user perchance have "multi core enhancement" or whatever the motherboard maker calls it enabled? Because with the default Intel setup the CPU should clock down to avoid temps like that. My 8700 cannot sustain 4.3 on all cores for more than a few seconds before it drops down to 3.7 and temps fall to under 60. It then stays there. This is with synthetic loads.
If you cannot manage cooling I would suggest disabling in BIOS the "multi core enhancement" (what Asus calls it).
With x264 via Plex mine turbos up to 4.3 and stays there if hardware trans-code is not an option.
