gpu: lock the memory clock at 810 MHz on the mining hosts (+13% on the 4090) #10

grenade · 2026-09-03T15:46:44Z

grenade commented

2026-09-03 15:46:44 +00:00

The miner never touches VRAM, so memory at full clock is watts taken from the SMs inside the same power cap. Measured with the CUDA engine, miner paused, interleaved rounds:

card	memory clock	MH/s	SM clock
RTX 4090 at 250 W	10,251 (default)	410	1,950
RTX 4090 at 250 W	5,001	435 to 447	2,040 to 2,175
RTX 4090 at 250 W	810	463	2,190
RTX 4090 at 250 W	405	155	645, low-power state
RTX 3060 at 130 W	7,301 (default)	81 to 82	1,725 to 1,800
RTX 3060 at 130 W	810	83 to 84	1,790

asset/gpu/nvidia-power-limit.sh: after the power limit, locks each card's memory clock at NVIDIA_MEMORY_CLOCK_MHZ (verified against the card's supported states; 405 refused), or resets it when unset, so the config is authoritative both ways.
script/infra-setup.sh: GPU_MEMORY_CLOCKS per host, written to the same config file. benjy and quadbrat at 810; beast deliberately absent since inference is memory-bound.
readme.md: the numbers and the 405 trap.

Already applied from this branch via the gpu role: benjy and quadbrat locked at 810 MHz without a miner restart, beast reset to default. nvidia-smi -lmc survives neither reboot nor driver reload, which is why it lives in this boot unit next to the power limit.

🤖 Generated with Claude Code

https://claude.ai/code/session_01CBgs2nSi4H2mdh8kD8vMX5

The miner never touches VRAM, so memory at full clock is watts taken from the SMs inside the same power cap. Measured with the CUDA engine, miner paused, interleaved rounds: | card | memory clock | MH/s | SM clock | | --- | --- | --- | --- | | RTX 4090 at 250 W | 10,251 (default) | 410 | 1,950 | | RTX 4090 at 250 W | 5,001 | 435 to 447 | 2,040 to 2,175 | | RTX 4090 at 250 W | **810** | **463** | 2,190 | | RTX 4090 at 250 W | 405 | 155 | 645, low-power state | | RTX 3060 at 130 W | 7,301 (default) | 81 to 82 | 1,725 to 1,800 | | RTX 3060 at 130 W | **810** | 83 to 84 | 1,790 | - `asset/gpu/nvidia-power-limit.sh`: after the power limit, locks each card's memory clock at `NVIDIA_MEMORY_CLOCK_MHZ` (verified against the card's supported states; 405 refused), or resets it when unset, so the config is authoritative both ways. - `script/infra-setup.sh`: `GPU_MEMORY_CLOCKS` per host, written to the same config file. benjy and quadbrat at 810; beast deliberately absent since inference is memory-bound. - `readme.md`: the numbers and the 405 trap. **Already applied** from this branch via the gpu role: benjy and quadbrat locked at 810 MHz without a miner restart, beast reset to default. `nvidia-smi -lmc` survives neither reboot nor driver reload, which is why it lives in this boot unit next to the power limit. 🤖 Generated with [Claude Code](https://claude.com/claude-code) https://claude.ai/code/session_01CBgs2nSi4H2mdh8kD8vMX5

grenade added 1 commit 2026-09-03 15:46:45 +00:00

gpu: lock the memory clock at 810 MHz on the mining hosts (+13% on the 4090) 1fbe9c5a6b

The miner never touches VRAM, so memory at full clock is watts taken from the
SMs inside the same power cap. Measured with the CUDA engine, miner paused:
4090 at 250 W 410 -> 463 MH/s (SM 1950 -> 2190 MHz); 3060 at 130 W 81 -> 83.
405 MHz drops the card into a low-power state (155 MH/s) and is refused.

Applied by nvidia-power-limit.service from the same config file
(NVIDIA_MEMORY_CLOCK_MHZ), configured per host in GPU_MEMORY_CLOCKS; hosts
without an entry are reset to the driver default. beast is not listed:
inference is memory-bound.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CBgs2nSi4H2mdh8kD8vMX5

grenade merged commit 8ee003d8d3 into main

2026-09-03 15:47:00 +00:00

grenade deleted branch gpu/memory-clock-lock

2026-09-03 15:47:01 +00:00

grenade referenced this issue from a commit

2026-09-03 15:47:02 +00:00

Merge pull request 'gpu: lock the memory clock at 810 MHz on the mining hosts (+13% on the 4090)' (#10) from gpu/memory-clock-lock into main

grenade referenced this issue from a commit

2026-09-03 15:47:19 +00:00

bench: record the memory clock alongside the SM clock (schema 2)

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