The patches related to the mitigation of meltdown and spectre attacks, have they caused significant and noticeable slow down of execution in systems they have been applied to?

  • Actually, performance loss is one of the few things that isn't covered in that answer @M'vy.
    – GdD
    Commented Jan 9, 2018 at 9:13
  • I know, but the idea is to gather these questions and get the answers in the same place. It should be added there, even as a new answer to that particular point. I'd advise to merge the answers there.
    – M'vy
    Commented Jan 9, 2018 at 9:18

2 Answers 2


The full impact isn't known yet. It is also going to differ massively based on workload - code invoking large numbers of system calls is likely to invoke a notable hit whilst any difference to code mostly operating in user mode is unlikely to be measurable.


There are not that many results, but for example Epic Games released a blog post that shows doubled CPU load on one of there cloud servers after installing the Meltdown mitigation. This is definitely significant and noticeable. But the overhead depends heavily on the workload. If it is noticeable by you can only be found out by you after patching.

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