AMD has confirmed that it is working hand-in-hand with Microsoft to address performance issues brought around by the use of non-uniform memory access (NUMA) in its high-end many-core Threadripper and Epyc processors under the Windows operating system.
Boasting 32 physical cores and 64 logical threads, AMD's Threadripper 2990WX - based on the server-oriented Epyc 7551 - should have been a chart-topping part for the high-end desktop (HEDT) and workstation market. Reviews, however, highlighted some serious issues in its real-world performance - particularly a failure to scale as you'd expect from the lower-end 16-core 32-thread part. An investigation by Level1Techs and Bitsum, though, found the source of the problem: a glitch in the Windows scheduler which could be worked around using a simple software tool, near-doubling the performance available to certain highly-threaded applications.
Now, AMD has spoken to Anandtech on the matter and brings glad tidings: The company is working closely with Microsoft to address the flaw, which it describes as 'very close' to the conclusions drawn by Level1Techs. AMD has promised it will make a public announcement once a patched scheduler or other update is available and that it will also bring additional performance improvements above and beyond those available using the Coreprio 'NUMA Dissociater' mode - though the company hasn't detailed exactly what these are nor how much real-world impact they will have.
In the meantime, the advice remains the same: Those running Windows on 32-core Threadripper or Epyc chips should use Coreprio's NUMA Dissociater mode to work around the issue.
April 9 2019 | 16:50