hyperthreading

[LuMiWa via freebsd-questions]

H1!

I have FreeBSD 13.0-RELEASE on Thinkpad T495. For now I had just Intel
processors and T495 has

Machine class: amd64
CPU Model: AMD Ryzen 5 PRO 3500U w/ Radeon Vega Mobile Gfx
No. of Cores: 8

I had hyperthreading disabled in boot/loader.conf:

machdep.hyperthreading_allowed=0
Is with AMD processors the same. I had also installed devcpu-data.
Should I do the same on the laptop, please?

Thank you.

[Pete Wright]

Post by LuMiWa via freebsd-questions
H1!
I have FreeBSD 13.0-RELEASE on Thinkpad T495. For now I had just Intel
processors and T495 has
Machine class: amd64
CPU Model: AMD Ryzen 5 PRO 3500U w/ Radeon Vega Mobile Gfx
No. of Cores: 8
machdep.hyperthreading_allowed=0
Is with AMD processors the same. I had also installed devcpu-data.
Should I do the same on the laptop, please?

yes i believe the same loader knob is used for AMD cpu's.  here's one of
my hosts with an Epyc CPU:
CPU: AMD EPYC 7302P 16-Core Processor                (3000.06-MHz
K8-class CPU)

$ sysctl machdep.hyperthreading_allowed
machdep.hyperthreading_allowed: 1
$ sysctl hw.ncpu
hw.ncpu: 32
$


cheers,
-pete

[LuMiWa via freebsd-questions]

On Thu, 15 Apr 2021 17:29:11 -0700

Post by Pete Wright

Post by LuMiWa via freebsd-questions
H1!
I have FreeBSD 13.0-RELEASE on Thinkpad T495. For now I had just
Intel processors and T495 has
Machine class: amd64
CPU Model: AMD Ryzen 5 PRO 3500U w/ Radeon Vega Mobile Gfx
No. of Cores: 8
machdep.hyperthreading_allowed=0
Is with AMD processors the same. I had also installed devcpu-data.
Should I do the same on the laptop, please?

yes i believe the same loader knob is used for AMD cpu's.  here's one
CPU: AMD EPYC 7302P 16-Core Processor                (3000.06-MHz
K8-class CPU)
$ sysctl machdep.hyperthreading_allowed
machdep.hyperthreading_allowed: 1
$ sysctl hw.ncpu
hw.ncpu: 32
$
cheers,
-pete

Thank you.