I gather that MCE (multi core enhancement) is only available on Z370 mainboards, but does the setting only apply to K CPUs? IE, is it benign on non-Ks?
Yes, it applies to non-K CPUs as well. Note however that it will push CPU beyond its normal limits, so if you apply it to non-K CPU you better equip it with good cooling unit or it will get hot.
Yes, it applies to non-K CPUs as well. Note however that it will push CPU beyond its normal limits, so if you apply it to non-K CPU you better equip it with good cooling unit or it will get hot.