pyrox.dev
lol
nixos/undervolt: adding undervolt module
We want to be able to configure persistent undervolting
in the NixOS configuration
+135
+1
nixos/modules/module-list.nix
+1
nixos/modules/module-list.nix
+134
nixos/modules/services/hardware/undervolt.nix
+134
nixos/modules/services/hardware/undervolt.nix
···
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{ config, pkgs, lib, ... }:
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with lib;
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let
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cfg = config.services.undervolt;
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in {
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options.services.undervolt = {
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enable = mkOption {
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type = types.bool;
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default = false;
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description = ''
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Whether to undervolt intel cpus.
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'';
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};
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verbose = mkOption {
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type = types.bool;
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default = false;
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description = ''
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Whether to enable verbose logging.
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'';
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};
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package = mkOption {
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type = types.package;
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default = pkgs.undervolt;
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defaultText = "pkgs.undervolt";
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description = ''
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undervolt derivation to use.
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'';
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};
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coreOffset = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The amount of voltage to offset the CPU cores by. Accepts a floating point number.
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'';
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};
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gpuOffset = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The amount of voltage to offset the GPU by. Accepts a floating point number.
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'';
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};
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uncoreOffset = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The amount of voltage to offset uncore by. Accepts a floating point number.
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'';
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};
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analogioOffset = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The amount of voltage to offset analogio by. Accepts a floating point number.
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'';
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};
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temp = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The temperature target. Accepts a floating point number.
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'';
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};
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tempAc = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The temperature target on AC power. Accepts a floating point number.
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'';
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};
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tempBat = mkOption {
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type = types.nullOr types.str;
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default = null;
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description = ''
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The temperature target on battery power. Accepts a floating point number.
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'';
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};
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};
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config = mkIf cfg.enable {
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boot.kernelModules = [ "msr" ];
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environment.systemPackages = [ cfg.package ];
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systemd.services.undervolt = {
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path = [ pkgs.undervolt ];
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description = "Intel Undervolting Service";
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serviceConfig = {
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Type = "oneshot";
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Restart = "no";
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# `core` and `cache` are both intentionally set to `cfg.coreOffset` as according to the undervolt docs:
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#
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# Core or Cache offsets have no effect. It is not possible to set different offsets for
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# CPU Core and Cache. The CPU will take the smaller of the two offsets, and apply that to
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# both CPU and Cache. A warning message will be displayed if you attempt to set different offsets.
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ExecStart = ''
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${pkgs.undervolt}/bin/undervolt \
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${optionalString cfg.verbose "--verbose"} \
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${optionalString (cfg.coreOffset != null) "--core ${cfg.coreOffset}"} \
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${optionalString (cfg.coreOffset != null) "--cache ${cfg.coreOffset}"} \
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${optionalString (cfg.gpuOffset != null) "--gpu ${cfg.gpuOffset}"} \
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${optionalString (cfg.uncoreOffset != null) "--uncore ${cfg.uncoreOffset}"} \
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${optionalString (cfg.analogioOffset != null) "--analogio ${cfg.analogioOffset}"} \
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${optionalString (cfg.temp != null) "--temp ${cfg.temp}"} \
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${optionalString (cfg.tempAc != null) "--temp-ac ${cfg.tempAc}"} \
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${optionalString (cfg.tempBat != null) "--temp-bat ${cfg.tempBat}"}
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'';
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};
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};
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systemd.timers.undervolt = {
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description = "Undervolt timer to ensure voltage settings are always applied";
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partOf = [ "undervolt.service" ];
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wantedBy = [ "multi-user.target" ];
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timerConfig = {
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OnBootSec = "2min";
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OnUnitActiveSec = "30";
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};
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};
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};
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}