www.2wires.com has a speed test meter. You can try it. In most cases, it should above 400-500k. Sometime I got 800k.
Usually, bandwidth limitation in the sever side is much smaller than the download speed limit of calbe (1.5Mbps for rogers) or DSL, so, the real speed you can get is much less than the cable BW limitaion. Some servers don't have or have a really high BW limiation, you can get it really fast. I downloaded the redhat linux from their offical server, a 660M size file cost about 2 hours.