Windows 10 PCs running the October 2018 Update are now getting improved Spectre fixes. This should speed up many PCs Microsoft slowed down with January 2018’s Spectre patches. This improvement, named “Retpoline,” was originally scheduled for Windows 10’s next update.
Technical information about how Google’s “Retpoline” works is available, but you don’t need to sweat the details. When implemented in Windows, it means the operating system can protect against Spectre attacks without a noticeable performance penalty.
We previously wrote that Spectre fix-related speedups would arrive with the forthcoming Windows 10’s April 2019 Update, also called 19H1. Now, Microsoft is slowly enabling this feature on current Windows 10 PCs—as long as they’re running the October 2018 Update. This is the first time these patches have been available on a stable version of Windows.
Over the coming months, we will enable Retpoline as part of phased rollout via cloud configuration. Due to the complexity of the implementation and changes involved, we are only enabling Retpoline performance benefits for Windows 10, version 1809 and later releases.
In other words, Microsoft will slowly enable Retpoline on small amounts of PCs at a time, ensuring it works properly—that’s the “phased rollout.” And it will only be enabled on your PC if you’ve upgraded to Windows 10’s October 2018 Update.
All PCs will get this improvement when they upgrade to the April 2019 Update according to Microsoft’s Mehmet Iyigun.
Today, we're starting our phased roll out of Retpoline performance optimization for Spectre variant 2 mitigations to Windows 10 1809. As we've shared before, Windows 10 19H1 will ship with Retpoline enabled by default.https://t.co/qCloXzDzWk#retpoline #spectre #windows
— Mehmet Iyigun (@mamyun) March 1, 2019
This feature is still disabled by default, and you probably don’t have it enabled even if you’re using the October 2018 Update. But, if those Spectre patches slowed down your PC, it should speed back up soon.