We're currently doing some tests FTP'ing a large file (3Gb) to the US, and are getting very mixed results in transfer time.  Some tests have taken 2.5 hrs, others have taken as long as 5 hours.

Our bandwidth to the internet is sufficiently large that the time - purely by calculation - should be lower, certainly a lot lower than 5 hours.  Our ISP says this wide variance is purely down to international web traffic, but I'm surprised to see a) such big differences depending on when it's being sent, and b) it taking as long as it's taking anyway, even at the shortest time of 2.5 hrs.

Has anyone else with decent size internet pipes (say at least 5Gbps upload), got any experience sending large files to the US?  If so, I'd be interested to know what kind of time it takes.

Thanks in advance.