In reply to @rampoina:matrix.org

[rampoina@nixos:~]$ cpupower frequency-info
analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 800 MHz - 3.90 GHz
  available cpufreq governors: performance powersave
  current policy: frequency should be within 800 MHz and 3.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 800 MHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

[rampoina@nixos:~]$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
powersave
powersave
powersave
powersave

I have

 musnix.enable = true;
  musnix.kernel.realtime = true;

so why wasn't it set to performance :|

[rampoina@nixos:~]$ LANG=EN_US journalctl -xeu cpufreq
~
~
~
~
~
~
~
~
~
~
Mar 12 19:19:27 nixos systemd[1]: Starting CPU Frequency Setup...
░░ Subject: A start job for unit cpufreq.service has begun execution
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░
░░ A start job for unit cpufreq.service has begun execution.
░░
░░ The job identifier is 98.
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 0
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 1
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 2
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 3
Mar 12 19:19:29 nixos systemd[1]: Finished CPU Frequency Setup.
░░ Subject: A start job for unit cpufreq.service has finished successfully
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░
░░ A start job for unit cpufreq.service has finished successfully.
░░
░░ The job identifier is 98

[rampoina@nixos:~]$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
powersave
powersave
powersave
powersave

[nix-shell:~]$ LANG=EN_US journalctl -x -b 0 | rg 'gover|cpu|powersave'
Mar 12 19:19:18 nixos kernel: setup_percpu: NR_CPUS:384 nr_cpumask_bits:4 nr_cpu_ids:4 nr_node_ids:1
Mar 12 19:19:18 nixos kernel: percpu: Embedded 57 pages/cpu s193920 r8192 d31360 u524288
Mar 12 19:19:18 nixos kernel: pcpu-alloc: s193920 r8192 d31360 u524288 alloc=1*2097152
Mar 12 19:19:18 nixos kernel: pcpu-alloc: [0] 0 1 2 3
Mar 12 19:19:18 nixos kernel: rcu:         RCU restricting CPUs from NR_CPUS=384 to nr_cpu_ids=4.
Mar 12 19:19:18 nixos kernel: rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
Mar 12 19:19:18 nixos kernel: x86/cpu: SGX disabled by BIOS.
Mar 12 19:19:18 nixos kernel: thermal_sys: Registered thermal governor 'bang_bang'
Mar 12 19:19:18 nixos kernel: thermal_sys: Registered thermal governor 'step_wise'
Mar 12 19:19:18 nixos kernel: thermal_sys: Registered thermal governor 'user_space'
Mar 12 19:19:18 nixos kernel: cpuidle: using governor menu
Mar 12 19:19:20 nixos systemd-modules-load[544]: Module 'cpufreq_performance' is built in
Mar 12 19:19:22 nixos kernel: cryptd: max_cpu_qlen set to 1000
░░ Subject: A start job for unit cpufreq.service has begun execution
░░ A start job for unit cpufreq.service has begun execution.
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 0
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 1
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 2
Mar 12 19:19:29 nixos cpupower[814]: Setting cpu: 3
░░ Subject: A start job for unit cpufreq.service has finished successfully
░░ A start job for unit cpufreq.service has finished successfully.
Mar 12 19:19:29 nixos audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=kernel msg='unit=cpufreq comm="systemd" exe="/nix/store/ahd7gadpy67gjiiqr2fwmhkf9wz7g2gw-systemd-251.12/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Mar 12 19:20:34 nixos kernel: Modules linked in: af_packet ip6_tables xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 msr ip6t_rpfilter ipt_rpfilter xt_pkttype xt_LOG nf_log_syslog xt_tcpudp nft_compat uvcvideo snd_seq_midi snd_seq_midi_event videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common snd_usb_audio nf_tables videodev intel_rapl_msr snd_usbmidi_lib uas libcrc32c mc input_leds nfnetlink mousedev joydev sch_fq_codel nvidia_uvm(PO) nvidia_drm(PO) intel_rapl_common nvidia_modeset(PO) intel_tcc_cooling x86_pkg_temp_thermal snd_hda_codec_realtek intel_powerclamp snd_hda_codec_generic snd_hda_codec_hdmi mei_pxp iTCO_wdt coretemp snd_hda_intel intel_pmc_bxt mei_hdcp snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec watchdog crc32_pclmul snd_hda_core mfd_core polyval_clmulni polyval_generic gf128mul snd_hwdep ghash_clmulni_intel ee1004 sha512_ssse3 sha512_generic snd_pcm drm_kms_helper e1000e aesni_intel 
...