https://arstechnica.com/gadgets/2021/10/windows-11-bug-could-reduce-ryzen-cpu-performance-by-up-to-15-amd-says/ Skip to main content * Biz & IT * Tech * Science * Policy * Cars * Gaming & Culture * Store * Forums Subscribe [ ] Close Navigate * Store * Subscribe * Videos * Features * Reviews * RSS Feeds * Mobile Site * About Ars * Staff Directory * Contact Us * Advertise with Ars * Reprints Filter by topic * Biz & IT * Tech * Science * Policy * Cars * Gaming & Culture * Store * Forums Settings Front page layout Grid List Site theme Black on white White on black Sign in Comment activity Sign up or login to join the discussions! [ ] [ ] [Submit] [ ] Stay logged in | Having trouble? Sign up to comment and more Sign up ryzen and fallin -- Windows 11 bug could reduce Ryzen CPU performance by up to 15%, AMD says Software fixes for the problems are coming later this month. Andrew Cunningham - Oct 7, 2021 3:20 pm UTC Windows 11 bug could reduce Ryzen CPU performance by up to 15%, AMD says Enlarge AMD reader comments 109 with 64 posters participating Share this story * Share on Facebook * Share on Twitter * Share on Reddit Most people shouldn't rush out to install brand-new operating system versions on day one, and Windows 11 is no exception to that rule. AMD has published information about a pair of bugs that can reduce performance for Ryzen processors running Windows 11 by as much as 15 percent, though how much slowdown you observe will vary based on what you're doing and the CPU you're using. AMD expects both bugs to be fixed later this month. The first issue AMD has identified increases L3 cache latency by up to three times, affecting apps that rely on fast memory performance. AMD says that most affected apps will slow down by between 3 and 5 percent but that some "games commonly used for eSports" could see dips of between 10 and 15 percent. AMD says that a Windows update will fix this issue later this month, so as long as you're checking for and installing Windows updates regularly, you won't need to do anything special to resolve the problem. Advertisement Further Reading Windows 11: The Ars Technica review The second bug is related to an AMD processor feature that tries to use your fastest individual CPU cores when running lightly threaded tasks rather than treating all cores the same. AMD doesn't put a number on this one but says the problem "may be more detectable" in processors with eight or more cores and a 65 W or higher TDP. This would include most 2000, 3000, 4000, and 5000-series Ryzen 7 and Ryzen 9 desktop CPUs and APUs. AMD says that a "software update," not a Windows update, will be released to fix the problem later in October, so you may need to install new AMD chipset drivers or some other software to get the fix. The AMD Ryzen issues are separate from performance slowdowns caused by some of Windows' virtualization-based security features. In particular, testing by outlets like Tom's Hardware has shown that the Memory Integrity security feature can reduce performance by a few percentage points in some games and general computing tasks, though the results vary widely based on the software you're using and the processor you have. The feature is included in both Windows 10 and Windows 11 but is disabled by default in both operating systems for all but the most recent laptops and desktops sold by major PC makers. reader comments 109 with 64 posters participating Share this story * Share on Facebook * Share on Twitter * Share on Reddit Andrew Cunningham Andrew is a Senior Technology Reporter at Ars Technica with over a decade of experience in consumer tech, covering everything from PCs to Macs to smartphones to game consoles. His work has appeared in the New York Times' Wirecutter and AnandTech. He also records a weekly book podcast called Overdue. Email andrew.cunningham@arstechnica.com // Twitter @AndrewWrites Advertisement You must login or create an account to comment. Channel Ars Technica - Previous story Next story - Related Stories Today on Ars * Store * Subscribe * About Us * RSS Feeds * View Mobile Site * Contact Us * Staff * Advertise with us * Reprints Newsletter Signup Join the Ars Orbital Transmission mailing list to get weekly updates delivered to your inbox. Sign me up - CNMN Collection WIRED Media Group (c) 2021 Conde Nast. All rights reserved. Use of and/or registration on any portion of this site constitutes acceptance of our User Agreement (updated 1/1/20) and Privacy Policy and Cookie Statement (updated 1/1 /20) and Ars Technica Addendum (effective 8/21/2018). Ars may earn compensation on sales from links on this site. Read our affiliate link policy. Your California Privacy Rights | Do Not Sell My Personal Information The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of Conde Nast. Ad Choices