9950X3D and gaming with CachyOS

General
1

Hey all,

Just made the switch from Win11 to CachyOS. So far so good. Davinci Resolve Studio 20 and Steam Games run OK.

One thought I had in mind is, on Win11, I was using an app called Process Lasso to force the games to use cores with X3D cache for the best performance. Is there a way in CachyOS to set this up?

I don’t want my games to use random CPU cores, only the ones with X3D for highest FPS. Similarly I want apps like Handbrake to use non-X3D cores.

2

There is Ferals Gamemode that allows to park cores but it seems to be discouraged so I came here with the same question.

Maybe someone else can answer it: What is the proper way to only use the X3D cores of a dual die CPU like the new AMD Ryzen X3D CPUs?

3

❯ for cpu in /sys/devices/system/cpu/cpu[0-9]; do
die=$(cat $cpu/topology/die_id)
echo "${cpu##/} → die_id: $die"
done | sort -V
cpu0 → die_id: 0
cpu1 → die_id: 0
cpu2 → die_id: 0
cpu3 → die_id: 0
cpu4 → die_id: 0
cpu5 → die_id: 0
cpu6 → die_id: 0
cpu7 → die_id: 0
cpu8 → die_id: 1
cpu9 → die_id: 1
cpu10 → die_id: 1
cpu11 → die_id: 1
cpu12 → die_id: 1
cpu13 → die_id: 1
cpu14 → die_id: 1
cpu15 → die_id: 1
cpu16 → die_id: 0
cpu17 → die_id: 0
cpu18 → die_id: 0
cpu19 → die_id: 0
cpu20 → die_id: 0
cpu21 → die_id: 0
cpu22 → die_id: 0
cpu23 → die_id: 0
cpu24 → die_id: 1
cpu25 → die_id: 1
cpu26 → die_id: 1
cpu27 → die_id: 1
cpu28 → die_id: 1
cpu29 → die_id: 1
cpu30 → die_id: 1
cpu31 → die_id: 1

you can use:
taskset -c 0-7,16-23 app

(this will make app use only CCD0 cores with SMT cores too)
for some games it will be even faster to use only taskset -c 0-7 app (only real cores)

of course, if X3D is on CCD0.

4

Is there any other option than using taskset? I’ve noticed some games won’t run with taskset.

5

never tried. 0 ideas, but here is what AI tells:

Alternatives to the Linux taskset command for managing CPU affinity and process CPU/core assignment include:

  • numactl: It controls NUMA (Non-Uniform Memory Access) policies, including process binding to CPU sockets and memory nodes. Unlike taskset, it does not change affinity of a running process but is useful for setting affinity at launch considering NUMA topology.
  • cpulimit: While it doesn’t bind processes to specific CPUs, it limits the CPU usage percentage of a process, indirectly controlling CPU load.
  • chrt and nice: These can adjust process scheduling priority rather than affinity and are mentioned as complementary to taskset in tuning CPU resource allocation.
  • Process Governor (Windows-focused but conceptually similar): A Python utility for managing process priorities and CPU/core affinity based on rules.
  • psutil: A Python module that provides interfaces for process and system monitoring including CPU affinity capabilities across platforms including Linux.
6

buy the way.. in BIOS there should be “gaming mode” option.. or something like this. it will do it’s thing.