Transfer 10 TB of files from USA to UK datacenter

Ship hard drives across the ocean instead.

At 11 Mbps with full utilization, you're looking at just shy of 90 days to transfer 10 TB.

11 Mbps = 1.375 MBps = 116.015 GB/day.

10240 GB / 116.015 GB/day = ~88.3 days.

I'd say rsync, at 11 MB/s you will look at 10-14 days and even if you get interrupted, rsync will easily start where it stopped last time.

At 11 Mbps I'd ship the hard disks like suggested above :)

Rsync of course.

At least you can continue at any time after a break, and it's without any pain.

Never underestimate the bandwidth of a station wagon full of tapes

-- Trad.

In your case, disks or tapes sent by courier, but the principle still applies. If you're not concerned about latency, this will be vastly cheaper than the network bandwidth to transfer 10TB of data in any reasonable length of time.