This affects every Intel processor since 1995 that implements out-of-order execution, except Itanium, and the Atom before 2013.
I would suggest taking a wait-and-see approach, because ultimately, benchmarks of the new operating system patches are the only accurate way to reliably determine if there will be any performance impact and if so, of what magnitude.
If you are a hosting provider that uses cloud services for your customers, expect your cloud provider to reboot systems during the coming days and have your operations team on standby to ensure that everything cycles back normally.
It is early in the year, but this may be the most important and impactful security vulnerability in 2018.
This affects any software running on Intel chips, no matter the operating system or vendor.
Google’s Project Zero (GPZ) is a think tank of leading edge security researchers who have established a track record of ground breaking research.