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cli_help.md

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Queries

  • --list, -l

    • List all devices and benchmarks without running them.

  • --help, -h

    • Print usage information and exit.

  • --help-axes, --help-axis

    • Print axis specification documentation and exit.

  • --version

    • Print information about the version of NVBench used to build the executable.

Device Modification

  • --persistence-mode <state>, --pm <state>

    • Sets persistence mode for one or more GPU devices.
    • Applies to the devices described by the most recent --devices option, or all devices if --devices is not specified.
    • This option requires root / admin permissions.
    • This option is only supported on Linux.
    • This call must precede all other device modification options, if any.
    • Note that persistence mode is deprecated and will be removed at some point in favor of the new persistence daemon. See the following link for more details: https://docs.nvidia.com/deploy/driver-persistence/index.html
    • Valid values for state are:
      • 0: Disable persistence mode.
      • 1: Enable persistence mode.

  • --lock-gpu-clocks <rate>, --lgc <rate>

    • Lock GPU clocks for one or more devices to a particular rate.
    • Applies to the devices described by the most recent --devices option, or all devices if --devices is not specified.
    • This option requires root / admin permissions.
    • This option is only supported in Volta+ (sm_70+) devices.
    • Valid values for rate are:
      • reset, unlock, none: Unlock the GPU clocks.
      • base, tdp: Lock clocks to base frequency (best for stable results).
      • max, maximum: Lock clocks to max frequency (best for fastest results).

Output

  • --csv <filename/stream>

    • Write CSV output to a file, or "stdout" / "stderr".

  • --json <filename/stream>

    • Write JSON output to a file, or "stdout" / "stderr".

  • --markdown <filename/stream>, --md <filename/stream>

    • Write markdown output to a file, or "stdout" / "stderr".
    • Markdown is written to "stdout" by default.

  • --quiet, -q

    • Suppress output.

  • --color

    • Use color in output (markdown + stdout only).

Benchmark / Axis Specification

  • --benchmark <benchmark name/index>, -b <benchmark name/index>

    • Execute a specific benchmark.
    • Argument is a benchmark name or index, taken from --list.
    • If not specified, all benchmarks will run.
    • --benchmark may be specified multiple times to run several benchmarks.
    • The same benchmark may be specified multiple times with different configurations.

  • --axis <axis specification>, -a <axis specification>

    • Override an axis specification.
    • See --help-axis for details on axis specifications.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

Benchmark Properties

  • --devices <device ids>, --device <device ids>, -d <device ids>

    • Limit execution to one or more devices.
    • <device ids> is a single id, a comma separated list, or the string "all".
    • Device ids can be obtained from --list.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --skip-time <seconds>

    • Skip a measurement when a warmup run executes in less than <seconds>.
    • Default is -1 seconds (disabled).
    • Intended for testing / debugging only.
    • Very fast kernels (<5us) often require an extremely large number of samples to converge max-noise. This option allows them to be skipped to save time during testing.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --throttle-threshold <value>

    • Set the GPU throttle threshold as percentage of the device's default clock rate.
    • Default is 75.
    • Set to 0 to disable throttle detection entirely.
    • Note that throttling is disabled when nvbench::exec_tag::sync is used.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --throttle-recovery-delay <value>

    • Set the GPU throttle recovery delay in seconds.
    • Default is 0.05 seconds.
    • Note that throttling is disabled when nvbench::exec_tag::sync is used.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --profile

    • Only run each benchmark once.
    • Disable any instrumentation that may interfere with profilers.
    • Intended for use with external profiling tools.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --no-batch

    • Do not run batched measurements even if enabled.
    • Intended to shorten run-time when batched measurements are not of interest.
    • Applied to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

Stopping Criteria

  • --timeout <seconds>

    • Measurements will timeout after <seconds> have elapsed.
    • Default is 15 seconds.
    • <seconds> is walltime, not accumulated sample time.
    • If a measurement times out, the default markdown log will print a warning to report any outstanding termination criteria (min samples, min time, max noise).
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --min-samples <count>

    • Gather at least <count> samples per measurement before checking any other stopping criterion besides the timeout.
    • Default is 10 samples.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --stopping-criterion <criterion>

    • After --min-samples is satisfied, use <criterion> to detect if enough samples were collected.
    • Only applies to Cold and CPU-only measurements.
    • If both GPU and CPU times are gathered, GPU time is used for stopping analysis.
    • Stopping criteria provided by NVBench are:
      • "stdrel": (default) Converges to a minimal relative standard deviation, stdev / mean
      • "entropy": Converges based on the cumulative entropy of all samples.
    • Each stopping criterion may provide additional parameters to customize behavior, as detailed below:

"stdrel" Stopping Criterion Parameters

  • --min-time <seconds>

    • Accumulate at least <seconds> of execution time per measurement.
    • Only applies to stdrel stopping criterion.
    • Default is 0.5 seconds.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --max-noise <value>

    • Gather samples until the error in the measurement drops below <value>.
    • Noise is specified as the percent relative standard deviation (stdev/mean).
    • Default is 0.5% (--max-noise 0.5)
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

"entropy" Stopping Criterion Parameters

  • --max-angle <value>

    • Maximum linear regression angle of cumulative entropy.
    • Smaller values give more accurate results.
    • Default is 0.048.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.

  • --min-r2 <value>

    • Minimum coefficient of determination for linear regression of cumulative entropy.
    • Larger values give more accurate results.
    • Default is 0.36.
    • Applies to the most recent --benchmark, or all benchmarks if specified before any --benchmark arguments.