Fastest way to separate the digits of an int into an array in .NET?

Question

I want to separate the digits of an integer, say 12345, into an array of bytes {1,2,3,4,5}, but I want the most performance effective way to do that, because my program does tha

Answer 1

1 + Math.Log10(num) will give the number of digits without any searching/looping:

public static byte[] Digits(int num)
{
    int nDigits = 1 + Convert.ToInt32(Math.Floor(Math.Log10(num)));
    byte[] digits = new byte[nDigits];
    int index = nDigits - 1;
    while (num > 0) {
        byte digit = (byte) (num % 10);
        digits[index] = digit;
        num = num / 10;
        index = index - 1;
    }
    return digits;
}

Edit: Possibly prettier:

public static byte[] Digits(int num)
{
    int nDigits = 1 + Convert.ToInt32(Math.Floor(Math.Log10(num)));
    byte[] digits = new byte[nDigits];

    for(int i = nDigits - 1; i != 0; i--)
    {
        digits[i] = (byte)(num % 10);
        num = num / 10;
    }
    return digits;
}