Do The Meltdown and Spectre Patches Affect PC Gaming Performance? 10 CPUs Tested

News
By Paul Alcorn
published

Test Setup

Our methodology for this story is fairly simple in practice. First, we performed a round of benchmarks on our Windows 10-based systems. Then, we applied the relevant patch and repeated the tests. Although the Variant 2 operating system patch we're using was deactivated via Windows, it should represent worst-case performance for now. We did not use a BIOS with Spectre mitigations because none are currently available (they were pulled). We'll follow up with more comparative testing as firmware updates arrive.

We tested each processor at its stock settings, including representatives from the Core i3, Ryzen 3, Core i5, Ryzen 5, Core i7, Ryzen 7, and Pentium line-ups. Naturally, overclocked systems will fare better. And as always, we disable Enhanced Multi-Core Turbo on our test systems.

In order to avoid variance from GPU Boost as our GeForce GTX 1080 heats up, we use multiple runs from each benchmark in quick succession. We select the median value from the last recordings, so, in many cases, the patched/unpatched results could land higher or lower than each other due to the tight variances you'll see today.


MORE: CPU Security Flaw: All You Need To Know About Spectre


MORE: Best Gaming CPUs


MORE: Intel & AMD Processor Hierarchy

Paul Alcorn
Paul Alcorn
Deputy Managing Editor

Paul Alcorn is the Deputy Managing Editor for Tom's Hardware US. He writes news and reviews on CPUs, storage and enterprise hardware.

31 Comments Comment from the forums
  • madvicker
    The majority of PC users are going to be on older CPUs than the ones you've tested. These results are only pertinent to the small % of people who have recently bought a CPU / new PC. What about the rest, the majority with older CPUs? That would be a much more useful and interesting analysis for most readers....
    Reply
  • nikolajj
    I would like to see this done with Intel gen 4 (maybe 3) and up.
    Reply
  • arielmansur
    Newer cpus don't get a performance penalty.. but older ones sure do get a noticeable one..
    Reply
  • salgado18
    20680472 said:
    The majority of PC users are going to be on older CPUs than the ones you've tested. These results are only pertinent to the small % of people who have recently bought a CPU / new PC. What about the rest, the majority with older CPUs? That would be a much more useful and interesting analysis for most readers....

    Last page, third paragraph:

    "so it's possible that the impact on older CPUs could be minor as well (game testing on those is in-progress)."
    Reply
  • ddearborn007
    Hmmm

    3/4 of all personal computers in the world today are NOT running windows 10. I don't know the exact percentage of gaming systems that are NOT running windows 10, but surely it is substantial.

    Why wasn't the performance hit measured on the operating system running 3/4 of all PC's in the world today published immediately? To date, it appears that these numbers are being withheld from the public; the only reason has to be that the performance hit is absolutely massive in many cases.........Oh, and out of the total number of PC's used world wide, "gaming" PC's are a very small percentage, again begging the question of why tests are only being published for windows 10....
    Reply
  • LORD_ORION
    Need to test older CPUs... or is this article designed by Intel to stop people from returning recently purchased CPUs.
    Reply
  • RCaron
    Excellent article Paul!

    I have a question.
    I read originally that AMD Zen architecture had near-immunity to Spectre variant 2 because a CPU specific code (password if you will) (that changes with each CPU) was required in order to exploit the CPU. Which is why AMD was claiming that Zen was almost immune to Spectre variant 2. Is this not the case?

    AMD continues to insist that Spectre 2 is difficult to exploit due to CPU architecture. You left this out, and you continually lumped AMD with Intel with respect to Spectre 2 vulnerability.

    This is misleading to your readers, and portrays a bias towards Intel.

    https://www.amd.com/en/corporate/speculative-execution
    Reply
  • tripleX
    20680748 said:
    Hmmm

    3/4 of all personal computers in the world today are NOT running windows 10. I don't know the exact percentage of gaming systems that are NOT running windows 10, but surely it is substantial.

    Why wasn't the performance hit measured on the operating system running 3/4 of all PC's in the world today published immediately? To date, it appears that these numbers are being withheld from the public; the only reason has to be that the performance hit is absolutely massive in many cases.........Oh, and out of the total number of PC's used world wide, "gaming" PC's are a very small percentage, again begging the question of why tests are only being published for windows 10....

    Global OS penetration for Win 10 and Win 7 is effectively tied.

    Reply
  • PaulAlcorn
    20680892 said:
    Excellent article Paul!

    I have a question.
    I read originally that AMD Zen architecture had near-immunity to Spectre variant 2 because a CPU specific code (password if you will) (that changes with each CPU) was required in order to exploit the CPU. Which is why AMD was claiming that Zen was almost immune to Spectre variant 2. Is this not the case?

    AMD continues to insist that Spectre 2 is difficult to exploit due to CPU architecture. You left this out, and you continually lumped AMD with Intel with respect to Spectre 2 vulnerability.

    This is misleading to your readers, and portrays a bias towards Intel.

    https://www.amd.com/en/corporate/speculative-execution

    From the AMD page (which you linked)

    Google Project Zero (GPZ) Variant 1 (Bounds Check Bypass or Spectre) is applicable to AMD processors.

    And...

    GPZ Variant 2 (Branch Target Injection or Spectre) is applicable to AMD processors.
    While we believe that AMD’s processor architectures make it difficult to exploit Variant 2, we continue to work closely with the industry on this threat. We have defined additional steps through a combination of processor microcode updates and OS patches that we will make available to AMD customers and partners to further mitigate the threat.
    AMD will make optional microcode updates available to our customers and partners for Ryzen and EPYC processors starting this week. We expect to make updates available for our previous generation products over the coming weeks. These software updates will be provided by system providers and OS vendors; please check with your supplier for the latest information on the available option for your configuration and requirements.
    Linux vendors have begun to roll out OS patches for AMD systems, and we are working closely with Microsoft on the timing for distributing their patches. We are also engaging closely with the Linux community on development of “return trampoline” (Retpoline) software mitigations.

    AMD hasn't released the microcode updates yet, but to its credit, it's probably better to make sure it is validated fully before release.
    Reply
  • DXRick
    Do the OS patches (without the microcode patches) fix the two exploits? If so, why would we even want the Intel patches at all?
    Reply