nvidia-laptop-gaming-tuning

name	nvidia-laptop-gaming-tuning
title	NVIDIA Laptop Gaming Performance Tuning (Linux)
description	Maximize gaming performance on NVIDIA Optimus laptops under Linux: enable Dynamic Boost (nvidia-powerd) when the driver ships no service/DBus policy, set up Feral GameMode, and handle the intel_pstate/EPP governor quirk.
triggers	["User wants better gaming/GPU performance on an NVIDIA laptop (Linux)","nvidia-powerd fails to start / \"not allowed to own service nvidia.powerd.server\"",{"GameMode \"Verifying CPU governor setting":"Failed\""},"Dynamic Boost not active on a laptop that supports it","CPU governor stuck on powersave on intel_pstate systems"]
version	1.0.0
author	Hermes Agent
license	MIT

NVIDIA Laptop Gaming Performance Tuning

Diagnostic First (always)

nvidia-smi --query-gpu=name,driver_version,clocks.max.graphics --format=csv
prime-select query                                    # should be 'nvidia' for max FPS
cat /proc/driver/nvidia/gpus/*/power | grep -i "Dynamic Boost"   # Supported?
systemctl is-active nvidia-powerd                     # Dynamic Boost daemon
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver   # intel_pstate?
cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference
powerprofilesctl get

CRITICAL: intel_pstate uses EPP, NOT the classic governor

On modern Intel laptops scaling_driver is intel_pstate in active mode. Here the scaling_governor string (powersave/performance) is NOT the real lever — the actual knob is EPP (Energy Performance Preference).

• powersave governor + EPP performance == effectively full boost.
• Blindly forcing the governor to performance does nothing useful.
• The real lever: set power-profiles-daemon profile to performance, which pulls EPP to performance on all cores. This needs no sudo:

  powerprofilesctl set performance   # EPP -> performance (max boost)
  powerprofilesctl set balanced      # EPP -> balance_performance (quiet)
  

• This is also why Feral GameMode's built-in governor switch FAILS on these systems ("Verifying CPU governor setting: Failed", pkexec "Not authorized"). Don't fight it — use GameMode custom hooks calling powerprofilesctl instead.

Fix: nvidia-powerd (Dynamic Boost) won't start

Symptom in journalctl -u nvidia-powerd:

Error requesting D-Bus name (Connection ... is not allowed to own the
service "nvidia.powerd.server" due to security policies ...)

Some driver packages (e.g. 595) ship the /usr/bin/nvidia-powerd binary but NOT the systemd service and NOT the DBus policy. Three things needed:

1. Service file — use the one the driver ships as docs (Type=simple!):

sudo cp /usr/share/doc/nvidia-kernel-common-*/nvidia-powerd.service \
        /etc/systemd/system/nvidia-powerd.service
sudo systemctl daemon-reload

Do NOT hand-write a Type=dbus unit — it hangs in activating waiting for a bus name. The official unit is Type=simple.

2. DBus system policy — /etc/dbus-1/system.d/nvidia-powerd.conf:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
  <policy user="root">
    <allow own="nvidia.powerd.server"/>
    <allow send_destination="nvidia.powerd.server"/>
    <allow receive_sender="nvidia.powerd.server"/>
  </policy>
  <policy context="default">
    <allow send_destination="nvidia.powerd.server"/>
    <allow receive_sender="nvidia.powerd.server"/>
  </policy>
</busconfig>

3. PERMISSIONS PITFALL — the DBus daemon runs as user messagebus/message+ and cannot read a -rw------- file. The policy MUST be world-readable:

sudo chmod 644 /etc/dbus-1/system.d/nvidia-powerd.conf
sudo pkill -HUP dbus-daemon        # reload policy
sudo systemctl enable --now nvidia-powerd
journalctl -u nvidia-powerd --since "30 seconds ago"   # want: "DBus Connection is established"

Note: a harmless ERROR! Error(1f) in setting the short timescale limit may appear — that's an optional register some laptops don't expose; Dynamic Boost still works.

Feral GameMode setup (auto perf on game launch)

sudo apt install -y gamemode
systemctl --user enable --now gamemoded

/etc/gamemode.ini (chmod 644!):

[general]
renice=10
ioprio=0
softrealtime=auto
[gpu]
apply_gpu_optimisations=accept-responsibility
gpu_device=0
nv_powermizer_mode=1
[custom]
start=/home/USER/bin/gamemode-start.sh
end=/home/USER/bin/gamemode-end.sh

Hooks (chmod +x), because the governor path is dead on intel_pstate:

# gamemode-start.sh
powerprofilesctl set performance
# gamemode-end.sh
powerprofilesctl set balanced

Test end-to-end:

gamemoderun bash -c 'cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference'
# should print: performance

Steam: per-game launch option gamemoderun %command% (also for Proton games).

Pitfalls

1. intel_pstate EPP quirk (see above) — biggest gotcha. Governor name lies.
2. DBus policy file MUST be chmod 644, not 600. messagebus can't read 600.
3. Use the driver's shipped Type=simple service, never a hand-rolled Type=dbus.
4. GameMode governor verification fails on intel_pstate — expected, use hooks.
5. powerprofilesctl needs no sudo for profile changes (local active session).