Memory allocation of the back-end grows quadratically with the system size

[Francesco Casella]

Consider the attached test package: it has one algebraic system of equations driven by a scalar differential equation.

Under Windows, the size of memory allocated by the back-end grows approximately as O(N²), N being the size of the algebraic system:

N	Memory (MB)
2000	260
4000	1000
6000	2000

Note that the number of non-zero elements in the incidence matrix of the system grows as O(N), as there are 3 non-zero elements in each row.

This is not sustainable for systems that have more than a few thousands unknowns.