Reason 3,995 to hold off on that Windows 11 upgrade: Iffy performance on AMD silicon

It's not as if gamers care about that sort of stuff

Chipmaker AMD has reported that some of its silicon lucky enough to have made the cut for Windows 11 is having difficulty with the new OS.

While not yet listed on Microsoft's known issues dashboard for Windows 11, AMD has come out and said that there's a performance penalty when running "certain applications."

The first issue is a potential three-times jump in L3 cache latency. Helpfully, AMD provided a clearer explanation: "Applications sensitive to memory subsystem access time may be impacted."

In practice, this is expected to result in a performance impact of between 3 and 5 per cent. Not so bad, until one considers "outliers" such as "games commonly used for eSports" where an impact of up to 15 per cent is possible. Less than ideal for the performance-obsessed gamer population.

Anyway, it's not like Microsoft ever bragged about how great Windows 11 was for gaming.

Oh, wait.

FTW tech response that puts high-performance gaming front and center. 🎮💚

— Microsoft (@Microsoft) October 1, 2021

Also not going to plan was functionality to schedule threads on a processor's fastest core, the impact of which would be felt more on CPUs with more than eight cores above 65W TDP (Thermal Design Power). "Applications sensitive to the performance of one or a few CPU threads," explained AMD, "may exhibit reduced performance."

Software and Windows updates are in the works to address both issues, and AMD said it was "actively investigating" the problems with Microsoft. Resolution is expected at some point in October.

In the meantime, AMD recommended customers affected hold off from that Windows 11 upgrade. As for which of its CPUs are actually hit, it simply said: "AMD and Microsoft have determined that compatible AMD processors may exhibit reduced performance in certain applications" and linked to a list of pretty much every bit of AMD silicon Microsoft had deigned to permit Windows 11 to run on. ®