I thought I should provide an answer. From my test this method is the fastest
public static class Helper
{
public static string[] HexTbl = Enumerable.Range(0, 256).Select(v => v.ToString("X2")).ToArray();
public static string ToHex(this IEnumerable array)
{
StringBuilder s = new StringBuilder();
foreach (var v in array)
s.Append(HexTbl[v]);
return s.ToString();
}
public static string ToHex(this byte[] array)
{
StringBuilder s = new StringBuilder(array.Length*2);
foreach (var v in array)
s.Append(HexTbl[v]);
return s.ToString();
}
}