Just released at the beginning of March of this year, AMD Ryzen has exceed expectations proving a performance level close or even better than we see in similar Intel processors, however with a notable exception.
Tested using the most popular PC games at the moment, AMD Ryzen processors have yielded weaker performances, which contradict the very good results obtained in other professional apps. After many days of confusions in which specialists have tried to find an expectations for the under performance of the new AMD Ryzen processors, Microsoft confirms a Windows 10 bug that poorly manages the resources provided by the AMD Ryzen processors.
Every AMD Ryzen processor packs 8 physical processing cores and an additional 8 virtual cores, totaling a number of 16 cores. Ideally, the operating system should allocate the 8 physical cores to apps first, followed by the 8 virtual cores so in order for the processor to be properly used. Some users have noticed that some processor cores are loaded more on AMD than on Intel, while under cores are not properly used or they are ignored by the native app.
Apparently, Windows 10 is unable to differentiate between physical and virtual cores in AMD Ryzen processors. Confirming this theory, some games have shown increased performance when SMT functionality ( simultaneous multi-threading ), alternative to Intel HyperThreading, is disabled from the motherboard BIOS.
Another aspect Windows 10 is not considering is the way AMD Ryzen processors are organized in 4 processing cores clusters, each sharing the L3 cache memory. So, a PC with an octa core procesosor ( AMD Ryzen 1800X for example ) works more like a dual socket system, housing two distinct quad core processors. To compare, the Intel Broadwell E processors have a monolith design with up to 10 physical processing cores sharing the same L3 cache memory.
In AMD’s case, the ineffective communication between the two modules that form the octa core Ryzen processor might be fixed if Windows 10 would consider its particularities, grouping apps to use a specific processing cluster. However, Windows 10 has the tendency of allotting resources at random, without considering possible hardware limitations.
With a bit of luck, Windows 10 might get a patch to fix these issues very soon so hang on tight as things are gonna get better.