I have been running an AMD Ryzen 5 1600X for a few month now and every once in a while I try to leave the Windows world behind me and switch to Linux. Unfortunately I have made extremely bad experiences as in my Ryzen 5 1600X was extremely unstable / practicable unusable with Linux.
First my system specs:
AMD Ryzen 5 1600X
Asus Crosshair VI Hero X370 (stable AGESA 220.127.116.11 BIOS installed)
Asus Strix GeForce GTX 1080 Advanced
G.Skill Flare X 16GB (2x8GB), DDR4-3200, CL14-14-14-34 (F4-3200C14D-16GFX)
Apart from defaults I was using the following BIOS settings in the past:
- RAM set to specs, was stable @3.200 MHz CL14 with AGESA 18.104.22.168 already but it's also extremely expensive "Ryzen" optimized memory @1.35V
- CPU VCore undervolted by negative offset of -0.14375V because this dramatically reduces power consumption when idle and even more on heavy loads (VCore in Windows with this setting is about 1.1V at max load and 1.35V with no load or XFR according to HWINFO instead of about 1.25V max load to 1.5V XFR with Auto on).
- SOC set to 1.0125V (below 1V 3.200 MHz isn't stable for RAM and AUTO voltage was well above 1.1V which is a bit exaggerated in my opinion)
- CSM Compatbility Support Module deactivated if that plays any role in system stability
My current host system was Windows 10 Pro Build 15063 running AMD Ryzen balanced power profile with latest drivers as of this writing installed. The above settings are absolutely rock solid in multiple heavy workload situations, e.g. Prime95 (any stress test) for hours, graphically challenging games such as Tomb Raider with ultra details @1440p or 3D Mark Time Spy stress test with running other cpu intensive tasks in the background such as video encoding, multiple Excel workbooks with extremely huge tables and complex power queries (heavy RAM and CPU workloads for 1-3 days) to name just a few examples. I didn't have a single crash, bsod or whatever on Windows 10.
Clonezilla and GParted
My plans with Linux started by trying Clonezilla and GParted (Debian based) in the latest versions as of this writing. With the above settings both crashed near instantaneously no matter whether I was booting from USB or CD/DVD. So my first thought was ok maybe one of the RAM issues so I downclocked to 2.133 MHz but it didn't change anything. Then I reset BIOS to save settings, i.e. no more undervolting which causes an idle power consumption of about +10-15% depending on operating system state (there is no real "idle" in Windows 10). This made Clonezilla and GParted at least boot into console mode, but as soon as I tried to e.g. clone a disk the system crashed after less than a minute (crashed = Asus Q-Code 8, i.e. CPU not operational or the system just hung up and didn't react to anything except the reset button of the case).
Fedora 26 (Kernel 4.12)
Fedora is a little more up to date than Clonezilla and GParted so I expected better results. Again with undervolting enabled the Fedora Live version didn't boot from USB or CD/DVD, the system just hung up during initialization. Because of the experience before I set undervolting to an offset of -0.1V which should actually run the CPU within AMD specs since the Asus board has default overvolting compared to specs (see above). Fedora booted but e.g. Prime95 crashed the system instantaneously with Asus Q-Code 8 = CPU not operational so I reset BIOS to defaults again with no undervolting and RAM @ 2.133 MHz which reduced RAM performance quite a lot and increased power consumption of course.
With BIOS settings back to defaults I could boot Fedora 26 and Prime95 could be started at least but the system still crashes now and then, sometimes even when there is no high load. Due to the instability and much higher power consumption on Linux (this is even true when running with default specs, see below) the Ryzen CPU is practically unusable on Linux for me.
Debian 9, Archlinux, openSUSE Tumbleweed
I can reproduce everything described with Fedora 26 with these systems as well so I can exclude a Fedora specific issue.
So ... am I holding it wrong ;-) or does Zen have an issue with Linux?
A little side note on power consumption
When run at default specs, i.e. no undervolting, power consumption on the Fedora Gnome Desktop was about 10% higher than on Windows 10 Desktop although Windows 10 has many more background services running. This is very disappointing to say the least, since it kills any usage and power consumption advantage vs. Intel for cheap Servers. If the same holds true for Threadripper then Zen has a serious issue, since Linux is much more common in the server world than Windows.