Memory Bank Conflict

int matrix[31250][2048];
for (int i = 0; i < 31250; ++i)
  for (int j = 0; j < 2048; ++j)
    sum += matrix[i][j];

var matrix: [31250][2048]i32 = undefined;
for (0..31250) |i| {
    for (0..2048) |j| {
        sum +%= matrix[i][j];
    }
}

int matrix[31250][2048];
for (int j = 0; j < 2048; ++j)
  for (int i = 0; i < 31250; ++i)
    sum += matrix[i][j];

var matrix: [31250][2048]i32 = undefined;
for (0..2048) |j| {
    for (0..31250) |i| {
        sum +%= matrix[i][j];
    }
}