LMbench

At a glance

• Editor score
  6.7 / 10
• Pricing
  Free plan
• Best for
  Low-level system latency and bandwidth analysis
• Free plan
  Yes
• Paid from
  Free
• Workload areas
  Bandwidth; latency; processor operations; memory hierarchy; cache; TLB; process and file-system operations; networking
• Facts checked
  23 Sep 2026

• Where it wins

  • Measures bandwidth across files, memory, pipes, TCP, and UNIX sockets
  • Analyzes latency, processor operations, cache, TLB, and memory parallelism
  • Includes a system-results database and configurable repeated runs

• Where it doesn't

  • Command-line builds and benchmark runs demand technical familiarity
  • Windows NT support is partial
  • Focuses on low-level measurements rather than turnkey PC scoring

Our verdict on LMbench

LMbench is an open-source suite of portable ANSI C microbenchmarks for UNIX/POSIX systems. It is intended for system developers and other technically advanced users who need to examine operating-system and hardware costs, rather than people looking for a simple overall PC score. Its workload spans bandwidth, latency, processor operations, memory hierarchy, cache, TLB, process and file-system operations, and networking. The breadth makes it relevant when the question is how individual system mechanisms perform, not just how one computer ranks against another.

The measurement depth is the main reason to choose LMbench. Bandwidth tests cover files, memory, pipes, TCP, and UNIX sockets; latency tests include connections, context switches, files, memory, processes, signals, system calls, and networking. It also measures processor operations and parallelism, and examines cache, cache-line, TLB, and memory parallelism. Configurable parallelism, warmup, and repetitions let technical users shape runs, while repeated runs and result-list generation support comparisons. An included system-results database provides a reference point, though the product's center of gravity remains component-level analysis rather than a turnkey interpretation of PC performance.

LMbench is open source and free, with local command-line build and execution and self-hosted deployment. Its listed operating-system coverage includes UNIX/POSIX variants such as Linux, FreeBSD, NetBSD, Solaris, SunOS, AIX, HP-UX, IRIX, and OSF/1; Windows NT support is partial. Documentation is the listed support channel. Choose it if you can work from the command line and want configurable, repeatable low-level measurements. If you need an easy-to-read overall PC score, or full Windows NT support, a different benchmark tool is a better fit.

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LMbench pricing

LMbench fact sheet

Alternatives to LMbench

• GGeekbenchA broad benchmark suite for comparing CPU and GPU performance across five platforms.9.3
• PassMark PerformanceTestA broad benchmark suite with free standard tests and a $39 one-time advanced tier.9.1
• 3DMarkA broad benchmark suite for comparing GPU, CPU, storage, and gaming performance.9.1

See all LMbench alternatives →

Featured on iTechGuides

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update