This is being very over exaggerated
I have an Intel i7 3770 and have been running the Windows Insider preview which has apparantly had the patch applied since November and I haven't noticed any performance drop in anything. Even testing since I heard of this I can't find anything more that 1-3% which can easily be for other reasons. Even gaming with a cpu intensive game (BF1 64player multiplayer on amiens) which maxes my CPU out I can't see any difference. Servers and virtualized enviroments might be different but there will be little or no effect on standard desktop use.