Which is better "nested if" or "if and multiple else if"?

Which code snippet has better performance?

Assuming that 'a' and 'b' are boolean variables.

First Code Snippet

if (a && b) {
    // path 1
} else if (a && !b) {
    // path 2
} else if (!a && b) {
    // path 3
} else {
    // path 4
}

Second Code Snippet

if (a) {
    if (b) {
        // path 1
    } else {
        // path 2
    }
} else {
    if (b) {
        // path 3
    } else {
        // path 4
    }
}

It seems that the second code snippet is doing less work but I don't know if nesting 'if conditions' have side-effects.