AMD Confirms Linux Performance Marginality Problem Affecting Some, Doesn't Affect Epyc / TR
Written by Michael Larabel in AMD on 7 August 2017 at 02:00 PM EDT. 273 Comments
AMD --
This morning I was on a call with AMD and they are now able to confirm they have reproduced the Ryzen "segmentation fault issue" and are working with affected customers.

AMD engineers found the problem to be very complex and characterize it as a performance marginality problem exclusive to certain workloads on Linux. The problem may also affect other Unix-like operating systems such as FreeBSD, but testing is ongoing for this complex problem and is not related to the recently talked about FreeBSD guard page issue attributed to Ryzen. AMD's testing of this issue under Windows hasn't uncovered problematic behavior.

With the Ryzen segmentation faults on Linux they are found to occur with many, parallel compilation workloads in particular -- certainly not the workloads most Linux users will be firing off on a frequent basis unless intentionally running scripts like ryzen-test/kill-ryzen. As I've previously written, my Ryzen Linux boxes have been working out great except in cases of intentional torture testing with these heavy parallel compilation tasks. Even when carrying out other heavy, non-compilation (GCC or Clang) parallel workloads in recent days, from server tasks to scientific processing, my Ryzen test boxes have been stable. I'm still using Ryzen 5 on my main desktop system without any faults in day-to-day use on Fedora 26 Linux.


AMD was also able to confirm this issue is not present with AMD Epyc or AMD ThreadRipper processors, but isolated to these early Ryzen processors under Linux. We will also now be receiving Threadripper and Epyc hardware for testing to confirm their Linux state. Their analysis has also found that these Ryzen segmentation faults aren't isolated to a particular motherboard vendor or the like, contrary to rumors/noise online due to the complexity of the problem.


Ryzen customers believe to be affected by the problem can contact AMD Customer Care. Some of those who have contacted customer care about the segmentation faults have in turn been affected by thermal, power, or other problems, but AMD says they are committed to working with those encountering this performance marginality issue under Linux. AMD will also be stepping up their Linux testing/QA for future consumer products.
About The Author
Author picture

Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter or contacted via MichaelLarabel.com.

Related AMD News
Popular News