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Spectre Patch Causes 'Significant Slowdown' On Older OS, Chips

Microsoft has begun updating its Windows operating systems against the Meltdown and Spectre vulnerabilities, but not all users will be too happy about it. According to the company, machines running Windows 7 and 8, as well as computers based on Haswell chips or older, will see “significant slowdowns” from the update. Intel’s own findings largely confirm Microsoft’s results.

Performance Decrease

From the earliest rumors, the performance decrease from Meltdown and Spectre ranged from negligible (2% or less) to significant (20% or more), on both Linux servers and Windows machines.

In our own tests, we saw that the Meltdown update didn’t have too much of an impact on storage performance, but it looks like Spectre is the patch that can slow down systems to a larger degree, especially if they are older.

Windows 10

Perhaps unsurprisingly, Windows 10 will be affected the least by the patches. This is due in part because Windows 10 is a more modern operating system, it comes with new modern hardware, and also because Microsoft has a bigger incentive to minimize the performance loss on the operating system that it keeps selling as a product to consumers and companies.

However, even on modern systems, Microsoft said that users should still see single digit percent slowdowns. The company doesn’t expect most users to notice this slowdown on modern hardware because we’re talking about milliseconds, but the performance degradation should be more apparent on older hardware.

Windows 7 And 8

Microsoft said that it expects most users of Windows 7 and 8 to see a significant drop in performance on their computers after the Meltdown and Spectre patches are applied.

Microsoft explained that the reason why Windows 7 and 8 are more impacted than Windows 10 is because the two use older kernels which perform more transitions between the kernel-mode and the user-mode. The Meltdown and Spectre patches add security checks in-between those transitions, which explains why the performance degradation is larger on these operating systems.

Microsoft didn’t say whether or not it would be possible to upgrade Windows 7 and 8 to the newer kernel. Presumably, it would take too much work to fix operating systems that are supposed to be discontinued in a few years anyway.

Windows Server

The company added that Windows Server will see “significant performance impact” when its enterprise customers will enable the mitigations to isolate untrusted code, especially in I/O intensive applications.

Haswell Chips And Older

No matter which version of Windows, machines that use 2015-era Haswell CPUs or older will experience “significant slowdowns,” according to Microsoft. The company also expects that most users will be able to notice that performance degradation. Skylake CPUs and newer have more refined branch prediction, so the Spectre patch doesn’t influence them to the same degree.

Intel’s Findings

Intel found similar results. Using top-of-the line Core i7-8700K consumer CPU with six-cores and 12 threats, a fast Intel 600p M.2 NVMe SSD, the company could still see a ~6% slowdown across the board in SYSmark benchmarks, which each individual benchmark ranging from 2%-14%.

Intel didn’t show how much more the patch will impact modern quad-core, dual-core CPUs, as well as older CPUs. However, if the overall performance of the 8700K drops by 6%, then it would make sense to see increasingly larger slowdowns on slower and older CPUs.

Microsoft and Intel’s message today seems clear: it's time to upgrade.

  • nostrocrompt
    *reads article*
    *looks at beautiful, over-achieving 5820k*
    *cries*
    Reply
  • Kennyy Evony
    I ran a test on my haswell system it said it wasn't vulnerable to the defects? win7 4790k cpu
    Reply
  • Math Geek
    i certainly noticed on my older machine. that was once i got it booting again after the patch torched the boot record and rendered it unable to boot to 1 of 2 OS's.

    fun fun fun
    Reply
  • takeshi7
    So has Intel given any hints to when they'll release a CPU that has this issue fixed?
    Reply
  • danwat1234
    Yep, so I won't be allowing the patch(es) on my Win7/8 computers at all. Risk is low. Performance and efficiency is very important to me.

    Mass public will tho... planned obsolescence conspiracy ;) . sub 10% performance gains in CPUs year over year average, oh but now your old computer sucks, gotta upgrade to 2017+ hardware..
    Reply
  • TadashiTG
    Typical Intel and Microsoft, they want people to spend money on their new products.
    Reply
  • Giroro
    "Microsoft and Intel’s message today seems clear: it's time to upgrade."

    To what, exactly? Neither company offers a product that fixes the security issue without degrading performance.
    Reply
  • InvalidError
    20577220 said:
    Typical Intel and Microsoft, they want people to spend money on their new products.
    Microsoft isn't making much money with Windows 10... it wanted to pass the billionth install mark in the first year with free upgrades to help it along and it only got half-way there over the first two years if I remember correctly. Probably the second slowest new Windows version adoption after Vista, perhaps third after ME.
    Reply
  • tpi2007
    Tom's Hardware, please don't inflate the problem before having done benchmarks and don't put words in Microsoft's mouth. Specifically:

    "According to the company, machines running Windows 7 and 8, as well as computers based on Haswell chips or older, will see “significant slowdowns” from the update."

    That is not what they said. This is:

    "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."

    https://cloudblogs.microsoft.com/microsoftsecure/2018/0...


    "significant" is not there, so you can't put quotes on that.


    Similarly here:

    "No matter which version of Windows, machines that use 2015-era Haswell CPUs or older will experience “significant slowdowns,” according to Microsoft."

    That's also not what they said and they differentiated between OS versions. To "some" users it will only be in "some benchmarks". And we already know how some benchmarks exaggerate the issue.
    Reply
  • CerianK
    Intel’s findings: “six-cores and 12 threats”

    Seems odd that Intel would admit it in that way. ??

    Anyway, I have 6/12 ‘threats’. Good thing I’ve got my Xeon W3690 OC locked to x29 multiplier already... maybe it won’t suck quite so bad if Win 10 forces nasty patches down my throat. Just to be clear: I run all of my cores all of the time doing research work... I will notice if a 10 day job suddenly takes a few extra days.
    Reply