Strassen's multiplication algorithm for n bits numbers (2way split vs 3way split) -

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there version of strassen's algorithm integer multiplication uses three-way split (division of n-bit number 3 parts of n/3 bits) , takes o(n^1.46).

my question why method not preferred usual 1 2 way split uses o(n^1.59)? ideas or links can me understand? (i looked online couldn't find anything)

that because in practise second 1 slower. o notation doesn't correspond real running speed.

example: 

f(n) = 1000*n g(n) = n*lg(n)

o(f(n)) better o(g(n)), making f(n) "faster", while in practise n never large enough prefer f(n).


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