AMD's Ryzen processors are now available, and with the embargo lifted, benchmarks have flooded the web. In most cases, the new hardware from Sunnyvale met expectations, but when it came to certain games, its numbers suffered a deeper impact than expected. Users discovered that disabling SMT improved performance a bit, which shifted suspicions to "scheduler" of Windows 10. Microsoft confirmed the existence of a bug, and it's estimated that a dedicated patch will come, but the question is how far the optimization will go.
At the end of the day, what was expected happened. From the beginning, we took the hype of leaked benchmarks with a grain of salt, waiting to see Ryzen's performance on various video games. And the numbers have spoken: Ryzen is an extremely convenient option to place eight cores on our desktops, but when it comes to pure FPS, Ryzen's largest model has a tough rival in the Intel Core i7-7700K, a Kaby Lake quad-core chip that costs $349 (without cooler). What happened? First, something already anticipated by AMD: Intel processors are stronger in IPC and single-thread operations. Then we found that very few games are truly optimized to use more than four cores, and third... Windows 10?
The SMT Discovery
According to available information, yes. The story began when some users decided to disable SMT support (the equivalent of Hyper-Threading on AMD) on their Ryzen chips, leaving the configuration at 8C/8T. When they repeated the benchmarks, these users saw that the numbers improved, and a series of exchanges with Microsoft via Twitter led the Redmond giant to confirm that "a new high-performance processor means new bugs to neutralize." In its detection process, scheduler of Windows 10 interprets Ryzen's 8C/16T as 16 physical cores. Any aspect of task priority between real and virtual cores is lost along the way, causing degradation.
More Issues to Address
Added to that are detection errors in the amount of available L2 and L3 cache, and conflicts between multipliers for low-power modes and the operating system's RTC. In other words, Microsoft has to eliminate several sharp edges with Ryzen. Problems with the scheduler date back to the birth of Hyper-Threading, and there were also issues after the launch of Bulldozer. Now, we must be realistic. Ryzen's performance will likely improve with a hotfix, but it may not be enough to surpass the 7700K, and the rest of the work will be left to developers. Even so, there is much enthusiasm for Ryzen's mid-range and low-end. I've said this before: If AMD can offer 75-80 percent of performance at half the cost, there will be high demand.
