On Wed, Mar 18, 2020 at 06:24:27PM +0100, Antony Stone wrote:
> Does anyone here have experience of running Devuan on AMD Ryzen CPUs?
>
> I'm just planning to get a new PC, and I've generally preferred AMD to Intel,
> so just wondering whether there's anything I need to look out for with pretty
> much the latest hardware.

Yes:

1. Upgrade your kernel to 4.10 or later. If you install the kernel
from Beowulf-backports, that should be good enough.

2. There is the linux ryzen crash. Type that into your favorite
search engine, and you'll get a whole bunch of info on it. Here's a
good page from those results:

<https://bugzilla.kernel.org/show_bug.cgi?id=196683>

To work around this, you have a few options:

a. Use the zenstates.py script to disable c6 state.

b. See if your UEFI has a Power Supply Idle Control setting, and set
it to typical if it does.

c. After experimentation, I've found that setting the CPU governor to
"schedutil", and leaving c6 enabled works fine for me, and gives me
the best of all worlds; c6 enabled, and no crashes.

3. There was a problem with the VME implementation on ryzen, which has
since been fixed:

<http://www.os2museum.com/wp/vme-fixed-on-amd-ryzen/>

That's all I can think of for now. You might want to check the
wikipedia ryzen page in case I forgot something.

Greg


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