Fewer FPS from October – This Windows Update Will Cost Performance in Your Games

Starting October 13, 2026, Microsoft will automatically enable a security feature in Windows 11 that many of you previously had to activate manually: Memory Integrity, also known in technical jargon as Hypervisor-Protected Code Integrity (HVCI). This feature aims to better protect the Windows kernel from rootkits and exploits but can noticeably reduce performance on some systems. As reported by GameStar, the performance loss on older or heavily utilized PCs can amount to up to around 15 percent FPS.

What is Memory Integrity and Why is Microsoft Activating it Automatically Now?

Memory Integrity is part of what's known as Core Isolation and uses virtualization-based security (VBS) to run critical processes in a sort of isolated sandbox. This makes it significantly harder for malicious software to embed itself deep within the system. You can find more details in the official Microsoft documentation on Core Isolation. On fresh Windows 11 installations, this feature is already standard on compatible hardware, as Microsoft explains in its information on Memory Integrity enablement. What's new is that the company is now gradually enforcing this protective function via updates on existing, already running systems.

How Much Will My FPS Really Drop Because of This Update?

On current hardware with modern CPUs, you'll generally notice little difference from the additional kernel protection, as the virtualization layer works efficiently with the processor. However, it's a different story for older or heavily utilized systems: Here, according to GameStar, the additional computational load can cost up to 15 percent of the framerate, especially in CPU-limited scenarios. This isn't an isolated incident that Windows users are only now facing: Windows updates repeatedly interfere with gaming performance in an unpleasant way, as our recent report on the Windows update that recently crashed Battlefield 6 demonstrated.

How Do I Manually Disable Memory Integrity in Windows 11?

If, after the update rollout, you notice your games stuttering or your FPS counter dropping significantly, you can try disabling the feature. Here's how:

• Open Windows Security (search in the taskbar or via Settings)
• Navigate to the Device security menu item
• Under Core isolation, click on Core isolation details
• Toggle the switch for Memory integrity to Off
• Restart your PC for the change to take effect

Afterward, a direct comparison is worthwhile: Start your favorite game once with and once without Memory Integrity enabled, and check your overlay's FPS display to assess the actual difference on your system.

Is the Performance Sacrifice Worth It for More Security?

The debate about security versus performance isn't entirely new for Windows: Even with the transition to Windows 11 22H2, virtualization-based security features like Core Isolation and VBS sparked discussions because they also cost performance on older hardware. For most gamers with modern PCs, the recommendation likely won't change much: Keep the feature active initially; it protects you from real threats at the kernel level. Only those playing on older or already tightly specced hardware who notice a clear FPS drop should, on a case-by-case basis, weigh whether a few extra frames per second are worth a slightly lower level of protection – and, if necessary, specifically deactivate the function.

Source: GameStar

Have you already received the update and noticed an FPS difference? Let us know in the comments!