The problems keep coming for Windows 11. Besides missing gaming features and a vote of no confidence by cloud PC providers, perhaps the worst of it has been a bug that drastically increases L3 cache latency on most AMD chips. That includes some of the best CPUs for gaming, like the Ryzen 5 5600X, and while both AMD and Microsoft have promised fixes, an unrelated Windows 11 update appears to have made the problem even worse.
The update in question was one of Microsoft’s ‘Patch Tuesday’ patches, which are usually small updates designed to squash bugs. In this case, though, the October 12th update – the first for Windows 11 – has instead given the AMD bug radioactive superpowers. TechPowerUp discovered that prior to the patch, their Ryzen 7 2700X was posting an L3 cache latency of 17ns, already a slowing-down of the usual 10ns, but the Windows 11 drove this up to 31.9ns. Whoopsie and, indeed, daisy.
It should be said that this wasn’t supposed to be Microsoft’s promised fix for the original latency issue, which is being developed separately to AMD’s own efforts and is still due for release this month. AMD have also now set a solid date for their own fix, October 19th, with a fix for another Windows 11 bug (relating to how tasks are assigned to CPU cores) scheduled for Octover 21st. Affected Ryzen owners should hopefully get some relief for their performance troubles very soon, then, unless something else goes wrong in the meantime.
In case it wasn’t sufficiently self-evident, any Windows 10 users planning to take Microsoft up on their free Windows 11 should arguably wait. If the risk of serious performance-sucking bugs wasn’t enough, headline features like DirectStorage are still waiting for usable implementation. I’ve used enough of the new OS on my testing rig to believe it will eventually be the Windows version to use, but that day still looks a ways off.