Microsoft has just published the first Tuesday patch for Windows 11. However, the update is far from resolving the problem of reduced performance of AMD processors, on the contrary. Indeed, it only worsens the situation. AMD announced the arrival of a hotfix on October 19.
As you may know, Windows 11 has just received its very first update, better known as Patch Tuesday. If the update in question corrected no less than 36 security flaws, owners of AMD processors expected it especially at the turn for a completely different reason.
Indeed, the final version of Windows 11 deployed since October 5, 2021 is encountering several problems with AMD SoCs. First, the OS can triple the rate of the L3 cache. This can lead to CPU performance drops of around 3 to 5% on many applications, while this loss rises between 10 and 15% on some games such as Dota 2 or Counter-Strike: Global Offensive.
In addition, a bug in the UEFI-CPPC2 functionality prevents the movement of threads to the highest performing core. In fact, the first Windows 11 update was eagerly awaited to correct these concerns. Only and as we learn from our colleagues on the TechPowerUp site, the latency of the L3 cache has further increased with the deployment of the new patch.
AMD processor performance continues to dip on Windows 11
Located at 10ns on Windows 10, the L3 cache latency had already risen to 17ns on Windows 11. And with the KB5006674 update installed, this latency increased to 31 ns on an eight-core AMD Ryzen 7 2700X processor! That is almost double. AMD confirmed the thing on social media and just announced the deployment of two patches between October 19 and 21, 2021 supposed to fix these performance issues.
It will be directly distributed via Windows Update, in other words no need for a specific utility. “The issue of CPPC2 has been resolved. A new AMD power plan is in the works and is expected to be released on October 21. […] The L3 cache latency issue has been addressed by Microsoft. Microsoft plans to publish the patch in its Windows Update 10C, scheduled for October 19 ”, assures AMD.