that and there's no need for 5Ghz as it'll require more than 1.4 vcore (in most cases) to achieve and there are countless threads/posts and so on about CPU's degrading QUICKLY above 1.4ish vcore. for extended periods.
what I mean by that is there were a lot that went OMFG!!!! SWEEEEET I got 5Ghz out of my CPU with only 1.45 vcore. then a few weeks later they were back crying that no matter what they did they couldn't get it stable again at 4.5ish with the same 1.45 vcore.
so my advice is to find your sweet spot for 1.375 ish vcore NOT OVER 1.4 and be happy there.