Ryzen Thread Scheduling is Just Fine says AMD

AMD has stated that the thread scheduling on the new Ryzen processor is working as intended. AMD says that it has investigated reports that claim incorrect thread scheduling is happening on the Ryzen parts. AMD wrote in a blog post, “Based on our findings, AMD believes that the Windows 10 thread scheduler is operating properly for Zen, and we do not presently believe there is an issue with the scheduler adversely utilizing the logical and physical configurations of the architecture.”

During the investigation into the alleged scheduling issues, AMD reviewed topology logs generated by Sysinternals Coreinfo utility. That part of the investigation determined that an outdated version of the application was where incorrect topology data that was reported in the media came from. Coreinfo v3.31 or later will give the correct results according to AMD.

AMD has also looked into evidence that had to do with performance deltas between Windows 7 and Windows 10 on the Ryzen chip. AMD says that it doesn’t believe there is an issue with scheduling differences between Windows 10 and Windows 7. AMD does states that there are applications out there that could better utilize the topology and capabilities of Ryzen CPUs with targeted optimizations, this is being worked on thanks to the over 300 Ryzen development systems that have been sampled globally says AMD.

AMD is also giving Ryzen 7 1700X and 1800X users new details on Temperature Reporting. That primary temperature reporting sensor for Ryzen is called T Control or tCTL. The temp given is derived by the junction Tj temp, which is the interface point between the die and heatspreader. AMD says that temperature might be offset on certain CPU models so all models on the AM4 platform have the same max tCTL value allowing a consistent fan policy.

The Ryzen 7 1700X and 1800X have a +20C offset between tCTL reported and actual Tj temps. Users of those parts can subtract 20C to get the true junctions temp for the processor, the 1700 needs no subtraction.