I tried to download a gigabyted file where I got 200~300 kb/s in my browser but the same link worked in wget over 6MB/s...Is there some magic behind the command?
wget normally works a little bit faster than Chrome because it's a terminal program so there is less resource usage overhead, but that would not explain such a large difference in download speeds between wget and Chrome. You probably have an issue with downloading that large file in Chrome. wget is a better tool than Chrome for downloading large files, if you don't have to solve a captcha in order to download the file.
