Large matricies

[Quell]

Hello.
I need to make a large matrix. somethign of size 1024 by 1024 and i need a couple of them. THe code works fine when i do thsi:

int matrix[3][1024][1024];

but when i make 3 arrays instead of a 3 dimensional array the program crashes.
ex:

int matrix[1024][1024];
int matrx[1024][1024];
int matry[1024][1024];

Any ideas how to circomvent this?
Thx