Windows 11's first big patch Tuesday is in the books. While the patch fixed plenty of problems, it made a performance issue with AMD CPUs worse than before the patch, which is never a good thing.
Last week, we reported that some AMD Ryzen CPUs were slower on Windows 11. With the release of the new patch, Microsoft did fix some nagging Windows 11 issues, such as the problem with Intel Killer networking, but it appears to have made AMD's problem worse.
The latest patch wasn't meant to fix the AMD issue yet, as that fix is scheduled to come later this month. However, it seems unlikely that making the problem worse was in the plans for Microsoft or AMD. That means that anyone running AMD Ryzen CPUs should continue to wait to upgrade to Windows 11, as the performance issues can be pretty substantial, especially for gamers.
TechPowerUp, which did the testing and first reported the issues getting worse, said, "In our own testing, a Ryzen 7 2700X 'Pinnacle Ridge' processor, which typically posts an L3 cache latency of 10 ns, was tested to show a latency of 17 ns. This was made much worse with the October 12 'patch Tuesday' update, driving up the latency to 31.9 ns."
That's a substantial difference and one that you'll definitely notice after you download and install Windows 11 on your PC. As much as no one likes waiting, the performance you'll retain by sticking with Windows 10 makes it worth the wait.
According to an AMD post that was shared on Reddit, the patch for the preferred core bug will arrive via a driver update on October 21, 2021. The L3 cache latency issue (which is the one made worse by this patch) will come through a Windows Update on October 19, 2021.