It seems that for a nonlinear map $f: \mathbb{R}^n \mapsto \mathbb{R}^n$ Newton's method solves (suppose f is sufficiantly smooth and solution exists) the nonlinear problem: for given $b$, find $a$ such that
$f(a)=b$.
with a initial guess $a_0$ sufficiently close to $a$.
Theoretically, the method converges quadratically to the exact solution $a$. But in actual numerical computation (Matlab etc.) if the number of unknowns $n$ is very large the method seems to be very slow and sometimes even do not converge quadratically.
Is there any recent development to overcome this shortcomings?