In [1]:
import os
os.environ["OMP_NUM_THREADS"] = "4"
os.environ["MKL_NUM_THREADS"] = "4"
os.environ["OPENBLAS_NUM_THREADS"] = "4"
import numpy
import time
In [2]:
def elementwise_product(x, y):
    assert(len(x) == len(y))
    z = numpy.zeros(len(x))
    for i in range(len(x)):
        z[i] = x[i] * y[i]
    return z

def broadcast_elementwise_product(x, y):
    return x * y
In [9]:
n = 1024 * 1024 * 128
x = numpy.random.rand(n)
y = numpy.random.rand(n)
In [5]:
t = time.time()
elementwise_product(x, y)
elapsed = time.time() - t
print("time elapsed: %f" % elapsed)

time elapsed: 0.260288
In [11]:
t = time.time()
for i in range(10):
    broadcast_elementwise_product(x, y)
elapsed = time.time() - t
print("time elapsed: %f" % elapsed)

time elapsed: 6.335351
In [12]:
n = 1024 * 16
p = 32
A = numpy.random.rand(n, n)
X = numpy.random.rand(n, p)
X1 = numpy.random.rand(n, 1)
In [13]:
t = time.time()
for i in range(10):
    numpy.dot(A, X)
elapsed_4t_mm = time.time() - t
print("time elapsed: %f" % elapsed_4t_mm)

time elapsed: 3.337421
In [14]:
t = time.time()
for i in range(10):
    numpy.dot(A, X1)
elapsed_4t_mv = time.time() - t
print("time elapsed: %f" % elapsed_4t_mv)

time elapsed: 1.092257

RESTART THE KERNEL

In [1]:
import os
os.environ["OMP_NUM_THREADS"] = "1"
os.environ["MKL_NUM_THREADS"] = "1"
os.environ["OPENBLAS_NUM_THREADS"] = "1"
import numpy
import time
In [2]:
n = 1024 * 16
p = 32
A = numpy.random.rand(n, n)
X = numpy.random.rand(n, p)
X1 = numpy.random.rand(n, 1)
In [3]:
t = time.time()
for i in range(10):
    numpy.dot(A, X)
elapsed_1t_mm = time.time() - t
print("time elapsed: %f" % elapsed_1t_mm)

time elapsed: 6.409531
In [4]:
t = time.time()
for i in range(10):
    numpy.dot(A, X1)
elapsed_1t_mv = time.time() - t
print("time elapsed: %f" % elapsed_1t_mv)

time elapsed: 1.237670
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