Windows 11 and AMD CPUs
Last week we reported that, at present, AMD processors suffer from some performance problems in Windows 11, especially in the gaming field. In fact, AMD itself has confirmed that losses of up to 15% could occur in certain workloads from Zen + CPUs upwards, i.e. from Ryzen 2000 onwards, including some EPYC chips for data centers and Athlon.Credit: AMD The problems are mainly due to two factors. The first relates to the latency of the L3 cache, which is practically tripled, leading to real performance degradation in games and applications. The bug has an impact on programs sensitive to the latency of the memory subsystem, causing a reduction of 3-5%, while in video games, especially those commonly used in eSports, as they are extremely sensitive to cache latency, this value can rise up to to touch 15%. Additionally, AMD's preferred core feature, which routes single-threaded applications to the two fastest cores on the chip, may not work as expected. This would primarily affect the performance of lightly threaded programs.
Credit: AMD AMD advised its users to “continue using a supported version of Windows 10“ to avoid such problems. Apparently, this advice will soon no longer be valid, given that, according to what was reported by colleagues at Wccftech, a new Windows 11 update will bea> released on October 19, which will also contain the patch that fixes the cache latency bug. L3. Later, a driver will also arrive that fixes the Collaborative Power and Performance Control (CPPC) problem, which is currently in the testing phase and has already been sent to OEMs, but should be available on the 21st of this month. Thanks to these two updates, finally even AMD users will be able to make the most of their processors on desktops and notebooks equipped with Windows 11.
Windows 11’s first update makes AMD CPU performance even worse
© Photo by Becca Farsace / The VergeAMD warned last week that its chips are experiencing performance issues in Windows 11, and now Microsoft’s first update to its new OS has reportedly made the problems worse. TechPowerUp reports that it’s seeing much higher latency, which means worse performance, after the Windows 11 update went live yesterday.
AMD and Microsoft found two issues with Windows 11 on Ryzen processors. Windows 11 can cause L3 cache latency to triple, slowing performance by up to 15 percent in certain games. The second issue affects AMD’s preferred core technology, that shifts threads over to the fastest core on a processor. AMD says this second bug could impact performance on CPU-reliant tasks.
The first Windows 11 update arrived yesterday
TechPowerUp measured the L3 cache latency on its Ryzen 7 2700X at around 10ns, and Windows 11 increased this to 17ns. “This was made much worse with the October 12 ‘Patch Tuesday’ update, driving up the latency to 31.9ns,” says TechPowerUp. That’s a huge jump, and the exact type of issue AMD warned about.
Patches for both of the Ryzen issues are coming before the end of the month, though. The L3 cache issue will likely be addressed next week by Microsoft, with rumors suggesting October 19th for a patch. The preferred core patch will be addressed by an AMD driver, which is expected to be delivered later this month and will hopefully be available on Windows Update as soon as it’s released.
It’s still surprising to see Windows 11 ship with these issues, especially when Microsoft has limited the amount of supported processors for this new OS. Bugs always happen with new OS releases, but such an obvious performance impact on key CPUs should have been picked up during the months of public beta testing. Either way, it’s encouraging to see this will be fixed very soon so those suffering from worse performance won’t have to wait too much longer for a patch.