cpufeature

Prototype of replacement for cpuinfo.py for high-performance Python modules. Detects CPU features such as:

• SIMD instruction support
• Number of cores (both virtual and physical)
• Cache sizes

It is fast, with an import+execution time of ~1 ms

It is written in C99. It supports Windows with MSVC and Linux with GCC/LLVM compilers. MacOSX should also work with GCC/LLVM but has not been tested.

It is licensed under Creative Commons Zero, so it may be freely incorporated as a submodule into your own projects.

It needs to be tested on a variety of machines.

Example

The module generates a dict called CPUFeature on import which contains useful information regarding optimization and compilation for the host.
For my Intel i7-7820X Skylake CPU, it generates the following info:

> python -c "import cpufeature; cpufeature.print_features()"
=== CPU FEATURES ===
    VendorId                : GenuineIntel
    num_virtual_cores       : 16
    num_physical_cores      : 8
    num_threads_per_core    : 2
    cache_line_size         : 64
    cache_L1_size           : 32768
    cache_L2_size           : 1048576
    cache_L3_size           : 11534336
    OS_x64                  : True
    OS_AVX                  : True
    OS_AVX512               : False
    MMX                     : True
    x64                     : True
    ABM                     : True
    RDRAND                  : True
    BMI1                    : True
    BMI2                    : True
    ADX                     : True
    PREFETCHWT1             : False
    MPX                     : True
    SSE                     : True
    SSE2                    : True
    SSE3                    : True
    SSSE3                   : True
    SSE4.1                  : True
    SSE4.2                  : True
    SSE4.a                  : False
    AES                     : True
    SHA                     : False
    AVX                     : True
    XOP                     : False
    FMA3                    : True
    FMA4                    : False
    AVX2                    : True
    AVX512f                 : True
    AVX512pf                : False
    AVX512er                : False
    AVX512cd                : True
    AVX512vl                : True
    AVX512bw                : True
    AVX512dq                : True
    AVX512ifma              : False
    AVX512vbmi              : False

Notes on Fields

• If num_threads_per_core > 1 likely Intel Hyperthreading (or equivalent architecture) is present. The physical core count may be unreliable in virtual environments.
• Cache sizes are in bytes.
• For AVX2, check AVX2 and OS_AVX2.
• For AVX512, check AVX512f and OS_AVX512. Python support for AVX512 instructions is highly limited outside of compilation with ICC. MSVC does not have AVX512 support until MSVC2017.

Authors

• Based on FeatureDetector by Alexander Yee (https://github.com/Mysticial/FeatureDetector).
• Ported to Python by Robert A. McLeod, who added detection of cores, and cache sizes.

Release Notes

0.1.1

• Fixes for compilation with clang.

0.1.0

• Added detection of processors, cores, and cache sizes
• Created Python wrapper around FeatureDetector
• Reduced FeatureDetector to C99 for better cross-platform compatibility