How to use NBminer for memory tweak? (Performance boost)

Understanding NBMiner Memory Configuration

1. NBMiner is a lightweight, high-efficiency mining software designed primarily for NVIDIA GPUs, supporting algorithms like Ethash, KawPow, and Octopus.

2. Memory tweak in NBMiner refers to adjusting GPU memory clock offsets, memory timings, and VRAM voltage parameters via external tools—NBMiner itself does not directly expose VRAM tuning interfaces.

3. Users rely on companion utilities such as MSI Afterburner or EVGA Precision X1 to apply persistent memory clock offsets before launching NBMiner.

4. A stable +500 MHz memory offset on RTX 3080 cards commonly increases hash rate by 3–5 MH/s on Ethash without triggering instability under proper thermal conditions.

5. Memory bandwidth utilization must remain below 95% during sustained mining sessions; exceeding this threshold often causes DAG load failures or intermittent kernel panics.

Core Parameters Affecting Memory Throughput

1. --mt flag controls memory timing mode: values range from 0 (auto) to 3 (aggressive), with higher numbers enabling tighter timings at the cost of reduced stability on older GDDR6 modules.

2. --mclock is not a native NBMiner argument but corresponds to the memory clock value set externally—NBMiner reads current GPU state at startup and adapts DAG loading accordingly.

3. The --pl parameter caps power limit; raising it to 110–115% allows memory controllers to sustain higher clocks under load without throttling.

4. --maxdual influences dual-mining memory allocation splits—incorrect values cause LHR unlock failure and erratic hashrate drops on locked 30-series cards.

5. Memory temperature thresholds above 90°C trigger automatic downclocking in most BIOS implementations, negating any manual overclock gains unless active cooling is optimized.

Stability Testing Protocol

1. Run NBMiner with -r 0 to disable auto-restart, then monitor for “GPU timeout” or “ECC error” messages in real time.

2. Use --log to capture 30-minute session logs, scanning for recurring “rejection due to stale share” patterns linked to memory latency spikes.

3. Validate consistency with --api-port 9001 and curl-based polling every 10 seconds to detect sub-10-second hash variance exceeding ±2.5%.

4. Stress test memory subsystem using CUDA-Z’s memory bandwidth benchmark side-by-side with NBMiner—results diverging by more than 8% indicate timing misalignment.

5. Check PCIe link width via nvidia-smi -q -d PCI; x8 or lower negotiated width correlates with increased memory controller contention and unstable DAG generation.

Common Memory-Related Failure Modes

1. “DAG verification failed” errors stem from corrupted memory writes during epoch transition—often resolved by lowering memory clock by 50 MHz increments until clean DAG loads occur across three consecutive epochs.

2. Random process crashes accompanied by “NVRM: Xid” error codes 31 or 69 point to GDDR6X memory controller faults, requiring BIOS-level memory voltage adjustment beyond NBMiner scope.

3. Hashrate decay over 45+ minutes with steady core clocks indicates thermal throttling of memory junctions—not visible in standard GPU temp sensors but detectable via GPU-Z’s memory junction temperature field.

4. Rejected shares spiking during pool difficulty adjustments suggest insufficient memory bandwidth headroom—observed when VRAM bandwidth usage exceeds 92% during DAG initialization phase.

5. Intermittent “CUDA error 700” occurrences correlate with mismatched memory timing profiles between GPU boot state and Afterburner-applied settings—requiring cold reboots instead of soft resets.

Frequently Asked Questions

Q: Does NBMiner support automatic memory tuning based on GPU model detection?A: No. NBMiner does not auto-detect or adjust memory parameters. All memory-related optimizations require manual configuration through third-party GPU utilities.

Q: Can memory tweaks improve performance on AMD GPUs using NBMiner?A: NBMiner does not support AMD GPUs. Its memory optimization workflows are exclusive to NVIDIA architectures with compatible drivers and firmware.

Q: Why does increasing memory clock sometimes reduce total hashrate despite higher bandwidth numbers?A: Excessive memory clocking introduces timing violations that force the GPU to retry memory fetches, increasing latency per DAG lookup and lowering effective compute throughput.

Q: Is it safe to apply memory voltage increases via VBIOS modification for NBMiner use?A: VBIOS modifications carry permanent hardware risk. NBMiner provides no safeguards against undervoltage-induced memory corruption or overvoltage-induced GDDR6X module degradation.