I use Jacop function for matrix of size 256x256
the matrix values are double
If I change the matrix value without change its size (256x256) what about calcuation time?
My mind says it should be same or near in every time
But actually it changes dramatically, why I do not know

Example

3.998 2.900 56.99
78.0 5.001 8.99
44.22 66.9 5.90

takes 10 ms
while this

1.00 7.88 20.11
0.111 2.00 1.00
0.321 1.02 6.09
takes 5 ms
why that? note that my matrix is 256x256