More info, thanks to Rotareneg at SBP forum for linking it:
https://www.reddit.com/r/sysadmin/co..._bug_incoming/
Most people are expected to be hit by losses in the one digit percent range. But in tests some get hit really hard, up to -50%, depending on the running tasks.
This is a real nasty way to start the year. Cloud computing: compromised. VM: compromised. The Linux patch seems to not have much effect on gaming under Linux, but effects on DirX remain to be seen. Certain other tasks under Linux however need to digest a massive blow in performance.