If you recently updated your Windows 10 PC and are now having problems in certain games, it may not be anything on your system that changed. The OS update Microsoft pushed on March 1 — KB4482887 (OS Build 17763.348) has known problems in certain games that are leading to massive performance issues. Some players report that certain games are now borderline unplayable as a result.
KB4482887 was supposed to be a mainstream quality-of-life improvement for Windows 10, with support for the “Retpoline” method of fixing Spectre and Meltdown and various reliability fixes. None of the issues mentioned appear to be particularly relevant to game performance. Even the Spectre and Meltdown patches shouldn’t be the culprit here. Gaming performance has never been shown to be significantly impacted by this kind of patching, Retpoline wasn’t expected to have this impact, and the support for Retpoline that Microsoft integrated into Windows 10 with this patch is disabled by default. You have to activate Retpoline on a supported version of Windows 10 with various registry switches, as discussed here.
The impact is specific to particular titles and does not appear to be a global issue with every game. Known-affected titles include Destiny 2, the one game Microsoft’s own bug report acknowledges may be affected. Other titles supposedly impacted include Sea of Thieves, Call of Duty 4, Call of Duty: Modern Warfare 2, and EA’s recently-released Apex Legends.
This last seems a little less well attested than the others, and I’m uncertain how true it is — the performance issues reported in Destiny 2 are massive, with frame rate drops of 50 percent or more. Apex Legends has been tearing up the download charts, however, and this patch has been available for a week. It seems likely that if it impacted Apex Legends as hard as it hits some other more established titles, the issue might have surfaced within 1-2 days. This is not a guarantee, however — it’s possible that whatever is causing this problem hits some titles much more than others, and that the slowdown in some games is comparatively modest. It could also be linked to how a game uses CPU time or other resources, meaning that whatever overhead or problem the bug is causing may simply be an issue some games deal with more gracefully than others.
Microsoft’s official guidance, if you are affected by this problem, is to uninstall the update and wait for a new patch to be released. Hopefully, you didn’t need any of the other fixes baked into the update before that happens. No non-gaming performance impacts have been reported from the new update, so those of you who aren’t gamers may not have anything to worry about.