Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
AMD Bug Microsoft Windows

AMD and Microsoft Issue Fixes For Ryzen CPU Slowdowns On Windows 11 (engadget.com) 34

Posted by BeauHD from the time-to-update dept.
AMD and Microsoft have issued patches to address the slowdowns reported with Ryzen processors when Windows 11 launched. Engadget reports: The latest chipset driver (version 3.10.08.506) should take care of the UEFI CPPC2 issue, which in some cases didn't "preferentially schedule threads on a processor's fastest core," AMD said. That could have slowed down apps that are sensitive to CPU thread performance. AMD noted that the problem was likely more noticeable in more powerful processors with more than eight cores and 65W or higher Thermal Design Power (TDP).

Meanwhile, Microsoft is rolling out a software update tackling a bug that increased L3 cache latency. The issue impacted apps that need quick memory access, which in turn caused CPUs to slow down by up to 15 percent. The patch, Windows 11 update KB5006746, will be available starting today, but at the time of writing, a page containing instructions for installing it isn't yet live. You should be able to install it via Windows Update too.
This discussion has been archived. No new comments can be posted.

AMD and Microsoft Issue Fixes For Ryzen CPU Slowdowns On Windows 11 More

AMD and Microsoft Issue Fixes For Ryzen CPU Slowdowns On Windows 11

Comments Filter:
  • I am stunned this kind of slowdown occurred by huge professional company.

    A chip that is a monster is made to run slower. Incredible.
    • > I am stunned this kind of slowdown occurred by huge professional company.

      That company was Microsoft, who hacked 'Windows 11' to make it run faster on Intel hardware:

      "AMD’s Ryzen processors based on the Zen, Zen+, and Zen 2 cores all share a common L3, but the structure of AMD’s CCX modules left the CPU functioning more like it had 2x8MB L3 caches, one for each CCX cluster, as opposed to one large, unified L3 cache like a standard Intel CPU." link [extremetech.com]
      • Windows ain't done until AMD won't run.

      • Oddly enough the problem occurs with Zen3 (aka ryzen 5000) CPU's as well, which no longer use CCX's and do have a unified L3 cache just like intel.

        A poster on overclock.net noticed that setting the cache sizes manually in the registry mostly fixes the problem, implying the problem is win11 incorrectly detecting cache sizes.
        https://www.overclock.net/thre... [overclock.net]

    • I am stunned this kind of slowdown occurred by huge professional company.

      A chip that is a monster is made to run slower. Incredible.

      Presumably because MS don't do QA and instead push it onto users who are more busy clicking about the screen rather than running benchmarks every single windows update to see if something is slower.

      The reality was this was fixed the day after it was discovered ... well the day after it was posted to Slashdot, so just a couple of days after it was discovered the fast ring release already corrected the performance issue.

      Also it doesn't help that Ryzen is quite a deviation from the way classic scheduling works

  • At least it's fixed, I was hesitant to install it knowing this issue was still present since my machine that runs Windows is a Ryzen system. I find this statement a little odd though: "didn't preferentially schedule threads on a processor's fastest core". I thought all cores were the same since this isn't a big.LITTLE style of architecture? Or is it that it is supposed to schedule them on cores that are physically further apart for heat dissipation?

    Disclaimer: Yes sometimes I use Windows for some things, n

    • Just like the same chips can be rated for the different speeds, different cores can be too. If you get a4 core 3.5Ghz chip, they guarantee the core will run at at least 3.5Ghz, but one core may run at 3.9 with no issue.
      • So the chips are binned based on the individual cores? As in each individual core of say a 12-core 5900x has its own speed rating? Is there a way to determine which/how many cores actually run at the rated max speed?

        • Re: (Score:2)

          by batkiwi ( 137781 )

          They can all run at the rated speed.

          Some can run faster than the speed on the box, and do so automagically when it can.

        • Re: (Score:2)

          by tlhIngan ( 30335 )

          So the chips are binned based on the individual cores? As in each individual core of say a 12-core 5900x has its own speed rating? Is there a way to determine which/how many cores actually run at the rated max speed?

          No, all cores can run at the rated speed. You buy a 3.5GHz chip, you can run all cores at 3.5GHz.

          However, AMD also tests each core to see if they can go faster in a single threaded workload. So your 4 core chip running at 3.5GHz might have cores able to do 3.6GHz, 3.7GHz, 3.6GHz and 3.8GHz. AMD

    • I thought all cores were the same since this isn't a big.LITTLE style of architecture? Or is it that it is supposed to schedule them on cores that are physically further apart for heat dissipation?

      Some cynical people would think that MS heavily optimized Windows 11 for Intel Alder Lake which has a big.LITTLE design and ignored AMD Ryzen. I would be one of those cynical people.

      • There's little separating the cynic from a conspiracy nutjob. The reality is AMD's Zen architecture is different (not different bad, but very much different better) than Intel and the classic way of doing things. Custom code is required. Custom code is usually the first thing to break during an upgrade. This issue was fixed in the Windows 11 fast ring literally a few days after discovery.

        News at 11.

        • Ummm new custom code was required to be written for Intel Alder Lake's big.LITTLE design. My contention is that MS did not prioritize optimization for current, available CPUs and focused on a new upcoming CPU. I do not think that rises to the level of "the Earth is flat" paranoia.

          • And? Bugs happen and get corrected. Again, literally fixed within a couple of days. The idea that this is some conspiracy to support Intel over AMD is just stupid. Do you know the reason why this wasn't even discovered until Windows 11's official release? Because outside of a few news organisations targeted at gamers literally no one sits and benchmarks every new Windows change.

            Problem discovered and fixed. Getting your panties in a twist about something so mundane may not be earth is flat paranoia, but cer

            • The idea that this is some conspiracy to support Intel over AMD is just stupid. Do you know the reason why this wasn't even discovered until Windows 11's official release? Because outside of a few news organisations targeted at gamers literally no one sits and benchmarks every new Windows change.

              And you are the one suggesting the conspiracy, not me. I only suggested that MS prioritized the new shiny over making sure their product worked with the current CPUs.

              Getting your panties in a twist about something so mundane may not be earth is flat paranoia, but certainly is "something something evil corporate conspiracy under the table deals" kind of paranoia, which just fails Occam's Razor. It doesn't fail the pub test though, but only because everyone in the pub is drunk and agreeable.

              Again, you are the one making it an issue. Strawman, much?

    • I thought all cores were the same since this isn't a big.LITTLE style of architecture?

      No. This was one of the departures from the classic ways of doing things. Zen has preferential cores and preferential CCXes. If you fire up Ryzen Master you will see them labelled telling you which core is capable of boosting the highest and which CCX group is as well.

      When Zen+ was released AMD worked with MS to introduce some custom patches to the windows scheduler to respect this way of identifying how to execute an instruction quickly. The other change is that Zen wakes and boosts cores in intervals far

  • Having the task centered on the task bar is really a step forward - very innovative. Not being able to right click for the Task Manager like we have for years brings you out of psychological flow so you can try to remember the right three key combinations - good brain training. And the way Chrome just locks up all the time requiring a reboot gives me more me time.

  • Nice shuffle, trying to blame AMD for a buggy Windows 11 hack to get it to run faster on Intel processors.

    "AMD’s Ryzen processors based on the Zen, Zen+, and Zen 2 cores all share a common L3, but the structure of AMD’s CCX modules left the CPU functioning more like it had 2x8MB L3 caches, one for each CCX cluster, as opposed to one large, unified L3 cache like a standard Intel CPU." link [extremetech.com]

    • Nice shuffle, trying to blame AMD

      No one blamed anything. They explained the core issue. It is a fact that AMD's Zen architecture was a departure from the standard way CPUs have operated and it is also a fact that AMD has worked with MS after the introduction of Zen+ with multiple patches to the OS, changes in power management, changes to the scheduler, etc to give them a speedboost.

      Specific custom stuff is often the first to break during a major upgrade. It's no surprise it broke. As for your conspiracy this was fixed literally within a co

Slashdot Top Deals

The biggest difference between time and space is that you can't reuse time. -- Merrick Furst

Close