I am a new dask user and I’m trying to run the function dot inside my program. I noticed that the function dot of dask is slower than its numpy version even when I use only one chunk in the whole matrix. How this behavious can be explained?
import dask.array as da
import numpy as np
x = da.random.normal(10, 0.1, size=(20000 * 100000), chunks=(20000 * 100000))
z = x.dot(x)
%time z.compute()
'''
CPU times: user 1min 1s, sys: 17.3 s, total: 1min 18s
Wall time: 52 s
'''
y = x.compute()
%time w =y.dot(y)
'''
CPU times: user 19 s, sys: 8.24 s, total: 27.2 s
Wall time: 767 ms
'''