Rumor: Is a Windows Bug Holding Back AMD Ryzen Performance?
The new AMD Ryzen processors have been out for a while now and while the three available CPU’s clearly gained the upper hand on comparable Intel CPU’s in multithreading performance, the CPU’s performed rather lackluster in other aspects. One of those aspects is gaming and particularly at lower resolutions, where Ryzen performance doesn’t seem to be able to match or outperform Intel’s chips.
However, those days might soon be over, as there have been rumors about Windows fully taking advantage of Ryzen’s horsepower. While it’s true that Windows and gaming titles can use further optimization to improve performance, there’s a good chance that a bug in the Windows 10 operating system is actually causing the performance issues with Ryzen.
Because Windows doesn’t fully comprehend that the SMT (Ryzen’s hyperthreading-like feature) simulated threads are weaker than the actual CPU cores, performance in games, for example, is limited. In some applications and benchmarks, Ryzen’s CPU performance was noticeably better when SMT was disabled. Microsoft seems to have acknowledged this bug in a Tweet, stating that a new high-end processor means that there new bugs to be neutralized. The Microsoft Support account promised to look into the issue and provide an update at a later time.
Furthermore, the Windows 10 scheduler seems to have diagnostic issues with AMD’s latest chips. The scheduler is the part of the operating system that divides assignments between all the cores, but it miscalculates the amount of cache memory each core actually can use. A Ryzen 7 CPU is being recognized as a CPU with a total cache of 136 Megabytes, while in reality the chip only contains 20 MB cache.
If these bugs are the reason why Ryzen doesn’t perform as expected/hoped in some aspects remains yet to be seen, but chances are that performance will improve thanks to further optimization nonetheless. In the early days of Intel’s HyperThreading, there was a noticeable speed difference in some non-multithreaded applications as well.