AMD Ryzen processors are not able to optimize on its Simultaneous Multi-Threading (SMT) technology because a bug in the Window 10 Scheduler is unable to differentiate its principal core threads from the virtual SMT threads. Microsoft has already acknowledged the problem and revealed that a fix is on the way, which many hope will be in the upcoming March 14 patch Tuesday update.
AMD just recently launched its Ryzen processors and benchmark results have been favorable to the Sunnyvale-based company particularly in multi-threaded workloads where AMD can leverage on its many cores. Ryzen has consistently posted an excellent performance-per-watt value, meaning optimal performance without consuming so much power. However, this is not the case with a Ryzen CPU in a Windows 10 system. Incidentally, Windows 7 is reported to be unaffected while it is unclear if Windows 8.1 also has the same problem.
It was just recently discovered that Windows 10 Scheduler is unable to correctly identify the components of the AMD Ryzen processor specifically its main threads from SMT threads. In short, Windows 10 Scheduler sees the 16 threads in the Ryzen 7 CPU as having 16 physical cores capable of equal resources per thread, wccftech has learned. In so doing, Scheduler does not give tasks to a principal core thread but assigns most of these to a virtual SMT thread, thereby reducing the overall performance of the CPU.
Moreover, Windows 10 Scheduler also thinks that every thread of AMD Ryzen is a core with its own L2 and L3 cache so it also mistakes the amount of cache available, according to Windows Report. As a result, it adds both L2 and L3 cache so Scheduler now thinks that the AMD Ryzen CPU has a total of 136MB of cache when in truth it only has 20MB when combining both caches. However, Microsoft has already been notified and the Redmond-based giant has already acknowledged the problem. It will be sending a patch soon possibly along with the patch Tuesday update on March 14.
In the meantime, AMD Ryzen CPU in Windows 10 can still be used. It may not perform as well as it should heavy workloads where the full power of the CPU is still compromised. For Windows 10 users, this may not be the best time to buy a Ryzen CPU while Microsoft has not yet issued a patch.
