you should wait a while for you pipe to empty again before you run another test. You did it within 1 min of each other. I don't want to explain the whole thing right now, but you have to wait. At least 5 min.
well when the test says my download rate is goes between 16mb-18mb/s and then to .4MB-2mb/s its not even close when my speed is 6MB which is around 790kbs