nvflux

Lock NVIDIA GPU memory and graphics clocks, safely.

git clone https://github.com/hmwassim/nvflux.git
cd nvflux
sudo ./install.sh
nvflux balanced

Log out and back in once after installing, so you can use nvflux without sudo.

What it fixes

Problem	Mode
HDMI/DP audio crackles, screen flickers, desktop lags	nvflux balanced
Loud fans, hot GPU, power use	nvflux powersave
Games or CUDA too slow	nvflux max
Undo	nvflux off

The mode is saved and applied again at boot and after sleep.

Commands

nvflux                        mode and clocks
nvflux info                   supported clocks, and what each mode sets
nvflux doctor                 check the setup
nvflux reload                 apply the saved mode again
nvflux lock memory <MHz>      lock the memory clock
nvflux lock graphics <MHz>    lock the graphics clock (or <min>-<max>)

--temporary   apply without saving    --gpu <N>   one GPU only
--force       allow a slow lock       --json      machine-readable output

See man nvflux for details.

$ nvflux balanced
GPU 0: balanced: memory 810 MHz, graphics 945-2100 MHz
$ nvflux
mode: balanced
GPU 0: NVIDIA GeForce RTX 3060
  memory      810 MHz  (locked 810)
  graphics    945 MHz  (locked 945-2100)
  power        17 W, 43 C

Safety

• It only uses NVIDIA's own clock-lock functions (nvidia-smi -lgc/-lmc use the same ones), with clock values the driver reports as supported.
• The driver's power limit and thermal protection always stay on. No overclocking, voltage, power limit or fan changes.
• Locks that would slow the GPU down are refused unless you add --force.
• Locks are released before sleep and applied again after.
• nvflux=off on the kernel command line boots without the locks.

Requirements

• The proprietary NVIDIA driver.
• Graphics locks: GTX 16 / RTX 20 or newer. Memory locks: RTX 30 or newer.
• Any distro, desktop and window manager. Boot hooks for systemd, OpenRC, runit, dinit and SysV; sleep hooks for systemd, elogind, zzz and pm-utils. doctor says what to do on anything else.

Permissions

nvflux is setuid root, mode 4750, group nvflux. Members of the group change clocks without sudo; everyone else uses sudo. The installer adds the user who ran it. sudo ./install.sh --everyone lets every user change clocks.

Uninstall

sudo ./uninstall.sh

It unlocks the clocks and removes everything the installer added.

Upgrading from the old nvflux

Run sudo ./install.sh. It removes the old autostart entries and keeps your saved mode: the old powersave becomes balanced (which does what it did), performance becomes max, auto becomes off. nvflux restore and nvflux lock <MHz> still work.

Help wanted

These can't be tested on the developer's machine. If you have one, run nvflux doctor and nvflux info --json and open an issue with the output:

• Laptops: does a lock survive the GPU powering itself off?
• Several or high-refresh monitors: does the driver keep memory above the lock?
• RTX 20 / GTX 16: do the graphics locks work?

Building by hand

make            # build/nvflux
make test       # unit, integration and installer tests (no root, no GPU)
make check      # static analysis and shell checks

License

MIT