There is mounting evidence that an Intel CPU bug, which could have lasting consequences for Amazon, Google, and other major cloud providers, is about to be disclosed. While a fix is in the pipeline, people say that it could impose performance penalties of as much as 35 percent. AMD chips are reportedly unaffected.
If I had to simplify this as best as possible, basically, for the last 10 years Intel “cheated” by sacrificing accuracy in CPU processing in order to gain performance. Where as AMD with their Phenom II, FX and Ryzen CPU’s focused on accurate processing at the sake of performance, and as such are not affected by the bug that leaves a gaping hole in security due to inaccurate calculations.
I’m looking forward to benching my i7 4790k, i7 3770k and i7 2600k against my FX-8350. The bright spot for Intel is that for newer chips (Skylake, Kabylake, Coffeelake) will be less severe.
tl;dr: there is presently an embargoed security bug impacting apparently all contemporary CPU architectures that implement virtual memory, requiring hardware changes to fully resolve. Urgent development of a software mitigation is being done in the open and recently landed in the Linux kernel, and a similar mitigation began appearing in NT kernels in November. In the worst case, the software fix causes huge slowdowns in typical workloads on Intel based machines.