Cable is fine.
Got a 20Mbit VM cable connection.
Typically used to only max about 7.2MBits and complained a couple of times to VM but they told me that I'd only ever see max speeds at 4am.
Ioverlooked several things though. :D While studying for a N+ decided it was best to ditch my wireless Netgear rangemax and try a "borrowed" cisco switch.
I then ditched the "mainstream" broadband testers in favour of a download manager & popular "legal" movie download site.(based in Russia although you have to pay $1.99 per movie :(...)
My next words were along the line "Holy flaking Christmas".
Downloaded a 690Mb AVI file in 4 Minutes 41 Seconds. :D That included about 20 seconds of sourcing time by the download manager.
Surely a fluke.
Tried it again with a different movie - exact same speed ~20MBits/second or roughly 2.5MBytes per second. Even during peak times.
Downloaded some MSDN software at a similar speed & just downloaded the ISO pointed out by Martin Richards above and it managed to build up to about 9Mbits/s before it finished through the download manager. I expect it could have gone higher as it found 19 sources but only managed to trigger 8 of them before the download completed(about 14 seconds).
Turns out my Netgear couldn't handle multiple connections.
Tried a belkin and it stopped responding when I sourced from 8 or more.
I thought I was tech savy but obviously I missed this one.