ha...
5 times faster:
float [] x = new float[1];
x[0] = 1.2345f;
System.Console.WriteLine(x);
byte [] dest = new byte[4];
System.Buffer.BlockCopy( x, 0, dest, 0, 4 );
System.Console.Write(dest[0] + "," + dest[1] + "," + dest[2]
+ "," + dest[3]);
System.Console.Read();