<< From cnet i am getting ~550kbps, from bandwidthspeedtest.com ~2Mbps, from pcpitstop.com ~1.2Mbps
which one of them is more accurate? >>
They all could be. There are more factors to actual download speed than how big YOUR pipe is. The farther away a place is and the more congested the link is the slower your speed will be. It all depends on where you download from and how many other people are downloading from there. The best advice I can give you is download something from your favorite download spot (ftp.openbsd.org in my case), see how fast it is, and use that as your speed.