Linux Kernel & System Performance Tweaks for Gaming: The Ultimate Unsafe Guide

Below is a single‑page cheat‑sheet that gathers every kernel‑level knob that people normally touch when they want raw performance – especially for games – and are willing to sacrifice security, stability and power‑saving.

For each item, you will find

How to read this documentMost of the entries are sysctl variables (/etc/sysctl.conf or a file under /etc/sysctl.d/). They can be applied instantly with sysctl -w … and made permanent by adding the line to a file that is loaded at boot.Some entries are kernel boot parameters – they belong on the GRUB_CMDLINE_LINUX_DEFAULT= line in /etc/default/grub and require a update‑grub + reboot.A few are userspace utilities (cpupower, tuned, systemd‑run, irqbalance, …) – they are started/stopped with systemctl.Reverting is simply the opposite: delete the line (or comment it), run sysctl -p (or sysctl -w for the temporary change) and/or rebuild the grub config and reboot.

1. CPU / Scheduler

2. Memory / VM

3. I/O / Disk

4. Network (for online games / Steam)

5. Security / Mitigations (the “big‑hammer” knobs)

6. GPU‑specific kernel tweaks

7. Miscellaneous “system‑wide” knobs

📦 How to apply all of the above in one go

Below is a copy‑paste ready script that assumes you are using a Debian‑/Ubuntu‑style system with grub, systemd, and the cpupower utility installed. Adjust the device names (sda, nvme0n1, card0, etc.) to match your hardware before running.

#!/usr/bin/env bash
set -e

# -----------------------------------------------------------------
# 1.  Kernel boot parameters (GRUB)
# -----------------------------------------------------------------
GRUB_CONF="/etc/default/grub"

# Add the parameters (append if already there)
NEW_PARAMS="intel_idle.max_cstate=1 nosmt nohz_full=1 mitigations=off \
nopti spectre_v2=off nospectre_v1 retpoline=off l1tf=off mds=off \
taa=off randomize_va_space=0 nokaslr nosmt isolcpus=2,3 \
elevator=none"

# Ensure we don't duplicate entries
if ! grep -q "$NEW_PARAMS" "$GRUB_CONF"; then
    sudo sed -i "s/^GRUB_CMDLINE_LINUX_DEFAULT=.*/& $NEW_PARAMS/" "$GRUB_CONF"
    echo "✔ Added kernel boot params to $GRUB_CONF"
fi

# -----------------------------------------------------------------
# 2.  Sysctl tunables (persistent)
# -----------------------------------------------------------------
SYSCTL_FILE="/etc/sysctl.d/99-gaming-performance.conf"
cat <<'EOF' | sudo tee "$SYSCTL_FILE"
# ---- CPU / Scheduler -------------------------------------------------
kernel.sched_min_granularity_ns = 1000000
kernel.sched_wakeup_granularity_ns = 1500000
kernel.sched_child_runs_first = 0

# ---- Memory ---------------------------------------------------------
vm.swappiness = 0
vm.vfs_cache_pressure = 50
vm.dirty_ratio = 5
vm.dirty_background_ratio = 2
vm.overcommit_memory = 1
vm.nr_hugepages = 1024
vm.max_map_count = 262144
kernel.randomize_va_space = 0
kernel.yama.ptrace_scope = 0

# ---- Transparent HugePages -----------------------------------------
vm.transparent_hugepage.enabled = always

# ---- Network ---------------------------------------------------------
net.core.rmem_max = 2500000
net.core.wmem_max = 2500000
net.core.rmem_default = 1250000
net.core.wmem_default = 1250000
net.ipv4.tcp_congestion_control = bbr
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_ecn = 0

# ---- Filesystem ------------------------------------------------------
fs.file-max = 2097152
fs.inotify.max_user_watches = 524288

# ---- Security --------------------------------------------------------
kernel.sysrq = 0
EOF

sudo sysctl --system
echo "✔ Sysctl parameters loaded"

# -----------------------------------------------------------------
# 3.  CPU governor & power settings
# -----------------------------------------------------------------
sudo apt-get install -y linux-tools-common linux-tools-generic cpupower
sudo cpupower frequency-set -g performance
echo "performance" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

# -----------------------------------------------------------------
# 4.  Disable services that move IRQs or swap
# -----------------------------------------------------------------
sudo systemctl disable --now irqbalance
sudo swapoff -a
sudo sed -i '/ swap / s/^/#/' /etc/fstab   # comment swap line

# -----------------------------------------------------------------
# 5.  GPU driver tweaks (example for NVIDIA – adapt for AMD)
# -----------------------------------------------------------------
# NVIDIA: create modprobe file
cat <<'EOF' | sudo tee /etc/modprobe.d/nvidia-performance.conf
options nvidia NVreg_RegistryDwords="PowerMizerEnable=0x0"
options nvidia NVreg_RegistryDwords="EnableCoolbits=28"
EOF
# Reload driver (requires you to be on a console, not inside X)
sudo rmmod nvidia_modeset nvidia_uvm nvidia_drm nvidia || true
sudo modprobe nvidia

# AMD: set power profile to performance (run after boot)
if [ -d /sys/class/drm/card0/device ]; then
    echo performance | sudo tee /sys/class/drm/card0/device/power_dpm_state
fi

# -----------------------------------------------------------------
# 6.  I/O scheduler & queue depth (example for /dev/sda)
# -----------------------------------------------------------------
for dev in /sys/block/sd*; do
    echo none | sudo tee "$dev/queue/scheduler"
    echo 64   | sudo tee "$dev/queue/nr_requests"
    echo 128  | sudo tee "$dev/queue/read_ahead_kb"
done

# -----------------------------------------------------------------
# 7.  IRQ affinity for main NIC (example NIC IRQ 45 → CPU2)
# -----------------------------------------------------------------
# Find the IRQ number for your NIC first: cat /proc/interrupts
# Then set a bitmask (CPU2 = 0x4)
# echo 4 | sudo tee /proc/irq/45/smp_affinity

# -----------------------------------------------------------------
# 8.  Final step – rebuild grub and reboot
# -----------------------------------------------------------------
sudo update-grub
echo "All done! Reboot now to activate the kernel boot parameters."

To revert everything:

1. Remove the file /etc/sysctl.d/99-gaming-performance.conf and run sudo sysctl --system.
2. Edit /etc/default/grub and delete the custom flags you added, then sudo update-grub.
3. Restore the CPU governor: sudo cpupower frequency-set -g powersave.
4. Re‑enable swap: uncomment the line in /etc/fstab and sudo swapon -a.
5. Re‑enable irqbalance: sudo systemctl enable --now irqbalance.
6. Remove GPU‑specific modprobe files and reload the driver.
7. Reset I/O scheduler to default (mq-deadline or bfq), e.g. echo mq-deadline | sudo tee /sys/block/sd*/queue/scheduler.

Caveats & Recommendations

Best practice – apply changes incrementally, test after each group, and keep a backup of the original configuration files (/etc/default/grub, /etc/sysctl.conf, etc.).

Quick reference table (compact)

TL;DR – What to try first for a noticeable gaming boost

1. Set CPU governor to performance.
2. Add mitigations=off and nosmt to GRUB (reboot).
3. Turn off swap (swapoff -a) and set vm.swappiness=0.
4. Use the bbr TCP congestion algorithm (sysctl -w net.ipv4.tcp_congestion_control=bbr).
5. Force the I/O scheduler to none on your SSD (elevator=none).
6. Give the GPU its “performance” power profile (echo performance > …).

These six steps alone usually give 5‑15 % lower frame‑time variance and a smoother gaming experience on most modern hardware.

Feel free to cherry‑pick the rest of the table for further fine‑tuning, but always keep a backup of your original configs and test after each change! Happy (fast) gaming!