According to Guru3D and several other media, AMD Ryzen processors are very fast with multithreaded workloads but not that powerful in games, which are CPU bound. On Twitter Microsoft now confirms the issue that Windows 10 does not detect the SMT threads accordingly, which could account for the performance difference.


In a tweet Microsoft seems to have confirmed the presence of this issue. Basically each core gets an extra thread (SMT simultaneous multi-threading). Compared to a physical core a virtual core is a little bit weaker, yet you still receive another thread visible to the operating system. In other words it looks like there is a bug related to the thread-scheduler within Windows.

According to Guru3D, disabling SMT in the BIOS helps increasing the performance marginally in some games. For example Rise of the Tomb Raider benefits from this change. Furthermore there might be more than one bug since the Windows 10 diagnostic tool fails to recognize the correct specification of the AMD 7 Ryzen CPUs. According to this tool, a 7 Ryzen CPU should have 136 MB combined cache while the CPU features only 20 MB for L2 and L3 caches.

A few years ago when Intel introduced Hyper Threading many similar issues have been addressed. Therefore we’re expecting that Microsoft is going to address the issues that have arisen with the new AMD CPUs, like they’ve taken care of the bugs with Intel’s Hyper Threading a few years back. So far it looks like it's just a matter of time until also the gaming performance of AMD’s Ryzen CPUs is on par with its Intel counterparts.

Let's hope that Microsoft fixes the scheduler and cache related issues as soon as possible. Maybe the upcoming patch, that has been scheduled for March 14 will fix them already.




Source: Guru3D