cmp50hx-unlock

cmp-tune — profile tuning

Sets power limit, core/memory VF offsets and the locked core-clock range from named profiles, per card. Optional; nothing in the unlock depends on it.

nvidia-smi cannot set VF offsets, so this talks to NVML directly through ctypes. No headers, no build step — it loads libnvidia-ml.so.1, which the driver already installs.

Commands

cmp-tune list                 # profiles in the config file
cmp-tune status               # live state + the ranges the card reports
cmp-tune show efficient       # what a profile would do, without doing it
sudo cmp-tune apply efficient
sudo cmp-tune reset           # back to card defaults

sudo cmp-tune -i 1 apply quiet   # one card only (default: every CMP card)

Profiles

Config is /etc/cmp-tune.conf (seeded from profiles.conf at install and never overwritten afterwards). Each section is a profile; every key optional:

Key	Meaning
`power_w`	power limit, watts
`core_offset`	core (GPC) clock VF offset, MHz
`mem_offset`	memory clock VF offset, MHz
`clock_min`	lower bound of the locked core clock, MHz
`clock_max`	upper bound of the locked core clock, MHz

[efficient]
power_w = 170
core_offset = 225
mem_offset = 1000
clock_max = 2100

Clock rules

Set only clock_max and the card’s own minimum supported clock becomes the floor. Set only clock_min and its maximum becomes the ceiling. So a profile never has to hardcode a bound it does not care about, and the lock always sits inside the card’s real range.
Set neither and no lock is applied; any existing lock is cleared.
Every value is validated against what the card reports. On a CMP 50HX that is 300..2100 MHz and 100..225 W, so:

$ cmp-tune show bogus
profile 'bogus' cannot be applied to GPU 0:
  - power_w 500 is outside the card's 100..225 W
  - clock_max 9000 is outside the card's 300..2100 MHz

Check the exact numbers for your card with cmp-tune status.

Which GPUs it touches

Only CMP 50HX (10de:1e09) and CMP 90HX (10de:220d), matched by PCI ID. Any other GPU in the box — a display card, another accelerator — is listed and skipped:

skipping GPU 1 (NVIDIA GeForce RTX 3090, pci 10de:2204): not a supported CMP card

Pointing -i at a non-CMP card is refused. With several CMP cards, the default is to apply to all of them; use -i for one.

Working with the idle governor

The idle governor and this tool drive the same NVML locked-clock setting, so on its own the governor’s release would clear a tuned clock and let the card boost past it (measured: 2145 MHz after a profile set 2100, because the VF offset stays live).

cmp-tune handles this: when it applies a profile with a clock lock it writes

/etc/systemd/system/cmp-idle-governor.service.d/10-cmp-tune.conf

with CMP_LOAD_CLOCK=min,max (and CMP_LOAD_CORE_OFFSET when the profile sets one) and restarts the governor, so its release restores exactly the profile’s clock and curve. cmp-tune reset removes it.

The core offset matters for idle power: a non-zero core VF offset pins the card in P0 and keeps memory at full clock, so the governor drops the offset while forcing P8 and puts it back on load. That is worth about 7 W per card compared with the old P3 workaround. Verified end to end: 2100 MHz under load → P8 idle → back to 2100 MHz, with the power limit and both offsets untouched throughout.

Pass --no-sync-governor to leave the drop-in alone.

Applying a profile at boot

Tuning is runtime state, so after a reboot the card is back at stock and the governor releases to the stock boost clock rather than your tuned one. To make a profile stick, enable the shipped unit:

sudo cp cmp-tune-profile.service /etc/systemd/system/
sudoedit /etc/systemd/system/cmp-tune-profile.service   # pick the profile
sudo systemctl enable --now cmp-tune-profile

It is ordered Before=cmp-idle-governor.service, so the CMP_LOAD_CLOCK drop-in is in place before the governor starts and the governor releases to the tuned clock. Nothing depends on the unit, so a failure does not block boot — but see the warning below before enabling it.

Notes and limits

Auto-apply at boot is opt-in on purpose: an unstable overclock that re-applies on every boot is awkward to recover from. Validate a profile interactively first, and keep in mind that systemctl disable cmp-tune-profile plus a reboot always gets you back to stock.
VF offsets shift the whole curve, so the effective clock under load can end up above clock_max unless a lock is in force. That is why a tuned profile should normally set a clock bound too.
Power limit and memory offset survive an idle-governor clamp/release cycle untouched. The core offset is deliberately dropped while idle and restored on load, so the card can reach P8 — see the governor’s README.
Values that a profile omits are left exactly as they are — a profile is not a full reset. Use cmp-tune reset for that, or a profile with no keys ([stock]).

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