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Microsoft Details Performance Impact of Spectre and Meltdown Mitigations on Windows Systems (microsoft.com)

Microsoft's Windows chief Terry Myerson on Tuesday outlined how Spectre and Meltdown firmware updates may affect PC performance. From a blog post: With Windows 10 on newer silicon (2016-era PCs with Skylake, Kabylake or newer CPU), benchmarks show single-digit slowdowns, but we don't expect most users to notice a change because these percentages are reflected in milliseconds.

With Windows 10 on older silicon (2015-era PCs with Haswell or older CPU), some benchmarks show more significant slowdowns, and we expect that some users will notice a decrease in system performance. With Windows 8 and Windows 7 on older silicon (2015-era PCs with Haswell or older CPU), we expect most users to notice a decrease in system performance.

Windows Server on any silicon, especially in any IO-intensive application, shows a more significant performance impact when you enable the mitigations to isolate untrusted code within a Windows Server instance. This is why you want to be careful to evaluate the risk of untrusted code for each Windows Server instance, and balance the security versus performance tradeoff for your environment.

For context, on newer CPUs such as on Skylake and beyond, Intel has refined the instructions used to disable branch speculation to be more specific to indirect branches, reducing the overall performance penalty of the Spectre mitigation. Older versions of Windows have a larger performance impact because Windows 7 and Windows 8 have more user-kernel transitions because of legacy design decisions, such as all font rendering taking place in the kernel.

5 of 237 comments (clear)

  1. Really? by Anonymous Coward · · Score: 1, Insightful

    This is why you want to be careful to evaluate the risk of untrusted code for each Windows Server instance, and balance the security versus performance tradeoff for your environment.

    This is a complete cop-out.

    People will need to balance their security against their performance.

    While this isn't MS's doing, it's Intel, MS is essentially side-stepping this and saying "bummer, dude, but you should decide if you need performance or security".

    No wonder this patch borked some systems, it sounds like it's something they half implemented, rushed out the door, and then threw up their hands.

    1. Re:Really? by Anonymous Coward · · Score: 5, Insightful

      What — exactly — do you expect Microsoft to do? They didn't make the hardware and they can't fix this in software. I believe the fact that they're offering the choice (on Server at least) of suffering the performance impact or not shows an extraordinary degree of pragmatism. I honestly can't imagine a better response; how would you have them change it?

  2. Re:Honest reasons why 'Windows 7' isn't good enoug by TheDarkMaster · · Score: 4, Insightful

    Windows 10 is a nice kernel but with an GUI made by preschool children on top of it... Maybe I change my mind and switch to it when the interface be made by real professionals, until then I'll continue with Windows 7.

    --
    Religion: The greatest weapon of mass destruction of all time
  3. Re:Only here by 110010001000 · · Score: 4, Insightful

    You are right. You can't expect Microsoft to fix their older operating systems that are under support. They just don't have the manpower or money. Everyone should just install Windows 10 (starts at only $119). And you also shouldn't expect Intel to fix their stuff either. It isn't like they have money to fix their stuff either. Just buy a new chip when it comes out. Problem solved.

  4. Re:Free speed upgrades for Appdoze 10! by Anonymous Coward · · Score: 2, Insightful

    Or better yet, don't run EOL software.

    Retard alert! Win7 has more than two years before EOL.