{
  config,
  lib,
  pkgs,
  service_configs,
  ...
}:
{
  boot.initrd.availableKernelModules = [
    "xhci_pci"
    "ahci"
    "usb_storage"
    "usbhid"
    "sd_mod"
  ];
  boot.initrd.kernelModules = [ "dm-snapshot" ];
  boot.kernelModules = [ "kvm-amd" ];
  boot.extraModulePackages = [ ];

  swapDevices = [ ];

  hardware.cpu.amd.updateMicrocode = true;
  hardware.enableRedistributableFirmware = true;

  # HDD I/O tuning for torrent seeding workload (high-concurrency random reads).
  # mq-deadline sorts requests into elevator sweeps, reducing seek distance.
  # Aggressive deadlines (15s) let the scheduler accumulate more ops before dispatching,
  # maximizing coalescence — latency is irrelevant since torrent peers tolerate 30-60s.
  # fifo_batch=128 keeps sweeps long; writes_starved=16 heavily favors reads.
  # 4 MiB readahead matches libtorrent piece extent affinity for sequential prefetch.
  services.udev.extraRules = ''
    ACTION=="add|change", KERNEL=="sd[a-z]", ATTR{queue/rotational}=="1", ATTR{queue/scheduler}="mq-deadline", ATTR{queue/read_ahead_kb}="4096", ATTR{queue/nr_requests}="512"
    ACTION=="add|change", KERNEL=="sd[a-z]", ATTR{queue/rotational}=="1", ENV{ID_ATA_ROTATION_RATE_RPM}!="0", RUN+="${pkgs.bash}/bin/bash -c 'echo 15000 > /sys$devpath/queue/iosched/read_expire; echo 15000 > /sys$devpath/queue/iosched/write_expire; echo 128 > /sys$devpath/queue/iosched/fifo_batch; echo 16 > /sys$devpath/queue/iosched/writes_starved; echo 4096 > /sys$devpath/queue/max_sectors_kb 2>/dev/null || true'"
  '';
}