5:21 PM - Ryzen
I wanted to share some thoughts on Ryzen bugs. As an early adopter of AMD Ryzen CPUs, I've had a lot of frustration with trying to boot non windows operating systems on them. I had assumed that it was simply a new platform and my OS needs some work. However, I did some research yesterday. Several different people have reported issues using Linux on Ryzen as well. Bash randomly crashes. GCC 4.6.x seems to trigger more problems than GCC 6 when compiling code. Matt Dillon of the DragonFly project even tracked down that there is a bug in SMT (AMD's hyperthreading equivalent) that is triggered when the CPU is under high load. Certain instructions occurring on one core while another thread is CPU bound can cause the entire system to crash. There's also a weird interaction with memory access in certain regions to a point that DragonFly and FreeBSD have had to move the trampoline to another location to avoid crashes!
DragonFly has already done at least 3 big ryzen patches and FreeBSD has 4 PRs open on it. AMD needs to get some serious micro code updates out for this thing.
Due to all of these problems, I'm not going to buy a ryzen CPU for my server as originally planned. I'm going to look at intel now.
I still think ryzen is a great platform for casual gaming and turning off SMT may improve reliability.