How to fully protect your Mac against Zombieland bug, and how badly the fix affects performance

“Want to protect your Mac against the Zombieland (MDS) bug?” Adrian Kingsley-Hughes reports for ZDNet. “According to Apple, becoming fully protected is not as simple as installing a patch.”

“Step one, however, is to install the latest updates, which are MacOS 10.14.5 for systems running Mojave, and Security Update 2019-003 High Sierra and Security Update 2019-003 Sierra for Macs running older operating systems,” Kingsley-Hughes reports.

“However, if you believe that you are at heightened risk of attack, Apple recommends that you disable hyper-threading on the CPU. And this comes with a huge performance cost, with Apple claiming ‘as much as a 40 percent reduction in performance with tests that include multithreaded workloads and public benchmarks,'” Kingsley-Hughes reports. “That’s a huge performance hit, and one that is likely to not only be noticeable, but have a major impact on how the Mac runs.”

Read more in the full article here.

MacDailyNews Take: Intel’s defective garbage is the gift that keeps on giving.

These Macs may be unable to be patched for future vulnerabilities similar to ‘ZombieLoad’ – May 16, 2019
How to protect your Mac from Intel CPU’s Microarchitectural Data Sampling (MDS) vulnerabilities – May 16, 2019
New secret-spilling flaw affects almost every Intel chip since 2011; Apple to release patches today – May 14, 2019
Macs may need ARM processors to survive – April 17, 2019
Researchers reveal new ‘Spoiler’ vulnerability in all Intel Core processors – March 6, 2019
Intel discloses new ‘Variant 3a’ and ‘Variant 4’ Spectre-like chip flaw vulnerabilities – May 22, 2018
Intel’s Spectre patch is causing reboot problems – January 12, 2018
In wake of Spectre and Meltdown, Intel CEO offers open letter, looks to restore confidence in Intel CPU security – January 11, 2018
Apple releases iOS and macOS updates with a mitigation for Spectre CPU flaw – January 8, 2018
Meltdown and Spectre: What Apple users need to know – January 8, 2018
How Apple product users can protect themselves against Spectre and Meltdown CPU flaws – January 5, 2018
Intel’s CEO Brian Krzanich sold off the majority of his shares after finding out about the irreparable chip flaws – January 4, 2018
Apple: All Mac systems and iOS devices are affected by Meltdown and Spectre security flaws – January 4, 2018
CERT: Only way to fix Meltdown and Spectre vulnerabilities is to replace CPU – January 4, 2018
Security flaws put nearly every modern computing device containing chips from Intel, AMD and ARM at risk – January 4, 2018
Apple has already partially implemented fix in macOS for ‘KPTI’ Intel CPU security flaw – January 3, 2018
Intel’s massive chip flaw could hit Mac where it hurts – January 3, 2018


  1. Can we have a moment’s silence for all those iMac Pro customers who have just had a sizeable chunk of their performance patched away…

    How does it feel to have your i7s patched to i5s? Look on the bright side, with Hyperthreading disabled Jony’s thermally constrained designs might not throttle the CPU anymore!!

  2. This might just be the impetus for Apple to fully commit, for good or bad, to Macs using Apple’s A-series chips. Not sure how severely that would impact Mac Pro plans since it would most likely also influence what peripheral cards would be supported.

    1. I don’t see why the implementation of A-series processors should impact peripheral cards. The motherboards will drives the interfaces and I/O chips will bridge the ports and card slots to the min processors.

      1. Drivers may be an issue. But that is something that Apple can address if it chooses to apply some of its software talent to the development of top-notch drivers.

  3. There is an opportunity here for AMD, if possible. I am pissed at Intel, that they have not worked hard enough to introduce new CPUs.

    Unfortunately AMD has real thermal issues. My rMBP, is hot enough. I can’t imagine how hot a similar AMD based rMBP might get.

    This brings us back to ARM processors, which is not something I’m looking forward to anyway. Regardless of an optimized OS for ARM, I don’t believe they will be as fast as Intel, hyper threading aside.

    How would you turn off hyper threading anyway?

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