import numpy as np
import timeit

N=4096

t_big=timeit.Timer('A.byteswap(True);A.tofile("a_big.bin")','import numpy;N={N};A=numpy.random.rand({N},{N})'.format(N=N))
t_little=timeit.Timer('A.tofile("a_little.bin")','import numpy;N={N};A=numpy.random.rand({N},{N})'.format(N=N))

print("Running for little endian...")
print t_little.repeat(5,10)

print("Running for big endian...")
print t_big.repeat(5,10)