The Home windows 11 bug may scale back Ryzen CPU efficiency by as much as 15%, says AMD



Most people shouldn’t be installing brand new versions of the operating system on day one, and Windows 11 is no exception to this rule. AMD has released information about two bugs that can reduce the performance of Ryzen processors with Windows 11 by up to 15 percent. However, how much slowdown you observe depends on what you are doing and what CPU you are using. AMD expects both bugs to be fixed later this month.

The first problem that AMD identified was increasing L3 cache latency by three times and affecting apps that rely on fast storage performance. AMD says that most of the apps affected will be slowed down by 3 to 5 percent, but that some “games often used for eSports” could see dips of between 10 and 15 percent. AMD says a Windows update will fix this problem later this month. So, as long as you are checking for and installing Windows updates regularly, you don’t have to do anything special to fix the problem.


The second bug is related to an AMD processor feature trying to use your fastest individual CPU cores when performing light-threaded tasks instead of treating all cores equally. AMD doesn’t give a number, but says that the problem “may be more noticeable” with processors with eight or more cores and a TDP of 65W or higher. This includes most Ryzen 7 and Ryzen 9 desktop CPUs and APUs from the 2000, 3000, 4000 and 5000 series. AMD says a “software update”, not a Windows update, will be released to address the issue later to fix in October. Therefore, you may need to install new AMD chipset drivers or other software to fix the problem.

The AMD Ryzen issues are separate from the performance degradation caused by some of the virtualization-based security features of Windows. In particular, tests at retail outlets such as Tom’s Hardware have shown that the memory integrity safety feature can reduce the performance of some games and general computing tasks by a few percentage points, although the results vary widely depending on the software and processor used. The feature is included in both Windows 10 and Windows 11, but is disabled by default in both operating systems for all but the latest laptops and desktops sold by major PC manufacturers.