Finite Element In Java - Computing Stiffness Matrix For ISOTROPIC Case

I build some finite element in java. I try to optimize my running time. I do some double loop and use inside the loop in if else statement and also in switch case .

The loop is very long, sometimes become ~500 X 500.

You think that if i avoid from the if statement and the switch case inside the loop i will improve the time calculation by at least 10%?There is something that i must to avoid ?

// Computing stiffness matrix.
switch (materialType) {
case ISOTROPIC:
// Computing stiffness matrix for ISOTROPIC case.
for (int row = 0, nvfi2 = nvfi * 2, index = 0, fieldsNvf = fields * nvfi; row < fieldsNvf; row++) {
if (row == nvfi) {
leftZeroMatrix = 3;

[Code] ....