Some of you may have been aware over the last few days of a major security issue that affects most Intel CPU's, some AMD CPU's and some ARM CPU's. https://news.sky.com/story/computers-face-global-slowdown-due-to-flaw-in-intel-chips-11193992 The story above is a bit sensationalist to be honest, but it does give you the gist of what's happening. Mac OS systems were patched a little while ago and Linux are now patched as well. Microsoft released it's patch for Windows10 yesterday, you can download the patch here : https://www.catalog.update.microsoft.com/Search.aspx?q=KB4056892 From what i have seen so far, the patch has very little if any slow down effect on desktop machines. Of course it is already well known that it has a dramatic effect on servers and VM's. I have an AM4 system running a Ryzen 1700 and patched mine this morning. I can't say i have noticed any slow down of the OS at all even after running loads of before and after benchmarks.