What speed plan are you on? Try one of the speed tests on this page:
http://www.t1shopper.com/tools/speedtest/#A
Try another here:
http://www.adslguide.org.uk/tools/speedtest.asp (this is a good one)
It's strange you couldn't get faster for the magnet link if you have a very fast connection. Remember 53 KB/s is equivalent to 424 kbps however you're going to lose some speed due to overheads (such as how far away you are from the exchange, or local traffic.)