What all-core clock speeds are being sustained under CInebench load? (If MCE enabled on a Z-series mainboard, sustained all-core 5 GHz can overwhelm some 240/280 radiators)
Disabling MCE (if enabled) would drop clock speeds to 'only' 4.7 GHz, whish is the 'stock' all -core turbo boost for all 8 cores, if applicable...