About Fisherfaces

I started to implement FisherFaces about a month ago. At this moment, I have succesfully implemented PCA for small matrices. The biggest simple matrix (not a proper image) I've tested has 5X5.

When it comes to proper images, i've encountered that my computer might not be good enough to obtain the eigenvalues of big matrices, when I run the code with a set of sample faces, my computer freezes after starting the PCA, more especificaly, it freezes when starting the eigenvalue decomposition of the matrices. I plan to run the code in a different machine, to see if  the error is a code error or if  it is just my computer not being able to handle it. If the latter is true, I would consider obtaining theeigenvalues via Matlab.