cpuminer: A Beginner’s Guide to CPU Mining Cryptocurrencies

Comparing cpuminer Forks: Which Version Is Best for Your CPU?cpuminer is an open-source family of CPU-based cryptocurrency miners (originally derived from Pooler’s cpuminer). Over the years, developers have created many forks optimized for different algorithms, instruction sets, and CPU architectures. Choosing the best cpuminer fork for your CPU depends on the algorithm you want to mine, your processor’s microarchitecture and instruction set (SSE/AVX), your operating system, and whether you prioritize raw hash rate, energy efficiency, or stability. This article walks through the major forks, their strengths and weaknesses, how to match a fork to your hardware, and practical tips to get the best results.

Quick summary: Which fork for which situation

• If you have a modern Intel CPU with AVX2 support: forks optimized for AVX2 will usually give the best hashrates on compatible algorithms.
• If you have an AMD Zen/Zen2/Zen3 CPU: choose forks that specifically include AMD optimizations (some forks include hand-tuned assembly or algorithm-specific paths for AMD).
• If you need broad compatibility and stability (older CPUs): use mainstream, well-maintained forks without aggressive CPU-specific optimizations.
• For low-power or embedded x86 systems: choose lightweight or stripped-down forks focused on efficiency.

Major cpuminer forks and what they offer

cpuminer-multi (and derivatives)

• Overview: A commonly used fork that supports a wide range of algorithms (e.g., scrypt, scrypt-jane, sha256d, x11, quark) and multiple platforms. Often used as a baseline for compatibility.
• Strengths: Broad algorithm support, active community history, cross-platform builds.
• Weaknesses: Not always the fastest for any single algorithm; generic builds might not exploit advanced SIMD extensions fully.

cpuminer-opt

• Overview: Focuses on optimized implementations for many algorithms, with CPU-specific code paths (SSE2/SSE4/AVX/AVX2). Maintained by contributors aiming for performance.
• Strengths: High hashrates on CPUs supporting modern SIMD; often the best choice for recent Intel/AMD desktop CPUs.
• Weaknesses: Some builds may be less portable; optimal performance requires compiling with correct flags for your CPU.

tpruvot’s cpuminer-multi (and forks)

• Overview: A widely adopted variant by tpruvot that improved compatibility and added new algorithms; many other forks branched from it.
• Strengths: Good balance between algorithm breadth and optimizations; commonly used in mining communities.
• Weaknesses: Performance may lag behind more aggressively optimized forks for specific CPUs.

cpuminer-gr (GeraldR) and other specialized forks

• Overview: Smaller forks that target specific coins/algorithms, sometimes including assembly optimizations or fixes for particular CPU families.
• Strengths: Top performance for their targeted algorithm/CPU combinations.
• Weaknesses: Narrow focus; may lack maintenance or multi-algorithm support.

Platform- or OS-specific builds (Windows, macOS, Linux)

• Overview: Some forks provide prebuilt binaries tuned for a platform. Others focus on building and packaging for a specific OS.
• Strengths: Convenience and better out-of-the-box performance for that OS.
• Weaknesses: Prebuilt binaries may not match your exact CPU microarchitecture; compiling yourself is often better.

How CPU features affect miner choice

• SIMD instruction sets (SSE2/SSE4/AVX/AVX2/AVX512): Algorithms that rely on vector processing benefit enormously when a miner fork implements these instruction sets. AVX2 support often yields the largest gains on supported processors.
• Cache size and latency: Some algorithms (especially memory-hard ones) are sensitive to L3 cache size and latency. AMD Ryzen CPUs (with large L3 caches) can hold advantages for such algorithms when a fork is tuned to exploit cache behavior.
• Number of cores/threads: Many cpuminer forks scale with threads. The efficiency of multi-threading and thread affinity can influence which fork performs better in multi-core systems.
• Power management and turbo behavior: Some forks or compile options allow disabling turbo or pinning frequency to reduce throttling and create more stable hashrates.

How to pick the right fork for your CPU — step-by-step

1. Identify the algorithm you want to mine (e.g., scrypt, x11, lyra2v2, RandomX-like algorithms). Algorithm choice often matters more than the fork.
2. Check your CPU capabilities:
   • Does it support AVX2/AVX512? (Modern Intel/AMD desktop/server CPUs often do.)
   • How many cores/threads? Cache sizes?
3. Shortlist forks known to implement optimizations for that algorithm and your instruction set (e.g., cpuminer-opt for AVX2-heavy performance).
4. Prefer forks with active maintenance and recent commits for security and compatibility.
5. Compile from source with CPU-specific flags:
   • For GCC/Clang: use e.g. -march=native -O3 (or specify -march= for precise tuning).
   • Enable SSE/AVX flags if not auto-detected.
6. Benchmark: run short tests with each fork, measuring hashrate, CPU usage, and power draw. Use identical conditions (same number of threads, pinned frequencies) to compare.
7. Choose the fork giving the best stable hashrate per watt for your goals.

Example compile and build tips (Linux)

• Install prerequisites: build-essential, autotools, libcurl-devel, libjansson (varies by distro).
• Common configure/build pattern:

  
  ./autogen.sh ./configure CFLAGS="-O3 -march=native" --with-curl make -j$(nproc) 

• For finer control, replace -march=native with a specific target (e.g., -march=znver3 for AMD Zen 3) to get tuned code generation.

Benchmarking methodology (recommended)

• Warm up the CPU for a few minutes to reach steady thermal/power state.
• Run each miner for a fixed interval (e.g., 5–10 minutes) and record average hashrate.
• Monitor CPU frequency, temperature, and power draw (if possible) to compare efficiency.
• Repeat tests at different thread counts (1, half cores, full threads) to find the best throughput/efficiency point.

Practical tips and caveats

• Prebuilt binaries: convenient but rarely optimal for your exact CPU. Prefer compiling for best results.
• Thermals: aggressive optimizations can push temperatures higher. Watch thermals to avoid throttling and instability.
• Power vs. hash rate: the highest hashrate may come at disproportionate power cost. For many miners, hashrate per watt is the more important metric.
• Security: only download forks from reputable repositories. Verify commits or use widely vetted forks.
• Algorithm changes & coin forks: mining profitability and algorithm popularity change. Choose miners that are maintained and adapt to new algorithm variants.

Comparison table (high-level)

Conclusion

There’s no single “best” cpuminer fork for all situations. Match the fork to the algorithm and your CPU’s instruction set and microarchitecture. For most modern desktops, cpuminer-opt or actively maintained tpruvot-derived forks compiled with CPU-specific flags will offer the best balance of performance and compatibility. For tight, algorithm-specific performance, look for specialized forks or patches targeted at that algorithm and CPU family—then benchmark to confirm which gives the best hashrate per watt for your setup.