mbw

Run 3 memory bandwidth tests with 512MB size

$ mbw -n 3 512

$ mbw -n 3 -q -a 512

$ mbw -n 3 -q -t[0] 512

$ mbw -n 10 -q -t[2] -b 1024 8192

$ mbw -n 0 -t[1] -q 2048

mbw [-h] [-n ] [-s ] [-t ]

-h
    Displays the help message and exits.

-n
    Specifies the number of iterations to run the benchmark. Default is usually a pre-defined value.

-s
    Sets the size of the memory buffer to be used in the benchmark in MB. A larger size may provide more accurate results, but consumes more memory.

-t
    Specifies the number of threads to use for the benchmark. Multiple threads can help expose the peak memory bandwidth.

mbw (Memory Bandwidth Benchmark) is a command-line tool used to measure the memory bandwidth of a system.

It allows users to assess the read and write performance of memory by performing a series of memory copy operations and reporting the transfer rate in MB/s (Megabytes per second).

This information is valuable for identifying potential memory bottlenecks and comparing the memory performance of different systems or configurations. mbw is commonly employed during system tuning, hardware evaluation, and performance analysis to optimize memory-intensive applications. It provides a quick and straightforward way to estimate the sustained memory bandwidth achievable under a specific workload.

The simplicity of mbw makes it suitable for automated benchmarking scenarios, particularly within embedded systems and resource-constrained environments where detailed performance monitoring capabilities may be limited.

The results of mbw can be affected by various factors, including CPU cache size, memory controller configuration, and other system processes running concurrently. Consider these factors when interpreting the output. Results will vary based on hardware and configuration.

The output of mbw usually shows the achieved memory bandwidth in MB/s for read and write operations. Higher values indicate better memory performance. Pay attention to variations between iterations to assess the stability of the results.
Example: A result of 'Read: 5000 MB/s, Write: 4800 MB/s' indicates a read bandwidth of 5000 MB/s and a write bandwidth of 4800 MB/s.

mbw can be used to quickly test the impact of different RAM timings, CPU clock speeds, and memory configurations on system performance. This is particularly useful when overclocking or tuning a system for optimal performance.

It also can be used in CI/CD to verify if performance requirements are still met.

hdparm(8), dd(1)