Let's put some light into the bits and bytes discussion.
A lot of people say.... Hey! My ISP said I have 4096/512 kbps speed. So how come, that my torrent client is showing 512/64 kB/s?
It is a simple answer.
Bit is a binary digit, taking a value of either 0 or 1. For example, the number 10010111 is 8 bits long, or in most cases, one modern PC byte. Binary digits are a basic unit of information storage and communication in digital computing and digital information theory.
So, as we see, the smart marketing people paid by ISPs are actually telling the truth. They are talking about bits. And they know, people love big numbers. So why should we say 512 kB/s download, when we can say 4 Mbps (4096 kbps). Huge numbers are better, a lot better for managers and salesmen.
So if you really want to know, what your speeds will be before you sign the next suped duper speed ISP contract, take a calculator, divide kbps by 8 and you will get the torrent client UL/DL speeds.
Here is also some more info about it http://www.t1shopper.com/tools/calculate/ and wikipedia http://en.wikipedia.org/wiki/Bit
Also google.com can help you just enter "4096 kb = ? kB" and change the 4096 with wanted conversion.
Hope this clears things a bit.