Question

为什么dgemm和sgemm比numpy的点慢得多（200x）？预期和正常吗？

以下是我用来测试的代码：

from scipy.linalg import blas
import numpy as np
import time


x2 = np.zeros((1000000, 512))
x1 = np.zeros((1, 512))

t1 = time.time()
for i in range(10):
    np.dot(x1, x2.T)
t2 = time.time()
print("np.dot: ", t2-t1)
t1 = time.time()
for i in range(10):
    blas.dgemm(alpha=1.0, a=x1, b=x2, trans_b=True)
t2 = time.time()
print("dgemm: ", t2-t1)
t1 = time.time()
for i in range(10):
    blas.sgemm(alpha=1.0, a=x1, b=x2, trans_b=True)
t2 = time.time()
print("sgemm: ", t2-t1)

我得到的结果是：

np.dot:  0.1820526123046875
dgemm:  34.11782765388489
sgemm:  25.33052659034729

以下是我的scipy配置，显示它是使用OpenBLAS编译的：

   >>> import scipy
    >>> scipy.__config__.show()
    openblas_lapack_info:
        libraries = ['openblas', 'openblas']
        library_dirs = ['/usr/local/lib']
        language = c
        define_macros = [('HAVE_CBLAS', None)]
    lapack_opt_info:
        libraries = ['openblas', 'openblas']
        library_dirs = ['/usr/local/lib']
        language = c
        define_macros = [('HAVE_CBLAS', None)]
    blas_mkl_info:
      NOT AVAILABLE
    openblas_info:
        libraries = ['openblas', 'openblas']
        library_dirs = ['/usr/local/lib']
        language = c
        define_macros = [('HAVE_CBLAS', None)]
    blas_opt_info:
        libraries = ['openblas', 'openblas']
        library_dirs = ['/usr/local/lib']
        language = c
        define_macros = [('HAVE_CBLAS', None)]

以下是我的numpy配置，与scipy的配置基本相同：

>>> import numpy
>>> numpy.__config__.show()
blas_mkl_info:
  NOT AVAILABLE
blis_info:
  NOT AVAILABLE
openblas_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]
blas_opt_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]
lapack_mkl_info:
  NOT AVAILABLE
openblas_lapack_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]
lapack_opt_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]

我使用它错了吗？

为什么dgemm和sgemm比numpy的点慢得多（200x）？

0 个答案: