Imagine that you want to deploy some components entirely within one Amazon Web Services (AWS) region – which region should you choose? Well, US-East is cheaper than EU-West (e.g. by 11.8% for the smaller on-demand instances), so that’s quite attractive – if your deployment is not tied for legal reasons to a European deployment. Obviously for most UK-centric organisations, the US is further away (!) and so network latencies should be greater…but are they? It seems obvious but before we ruled out a potential 10%+ saving for our customers, we thought we’d do some measurements.

And the answer is…

us-east-1d, average round trip time = 231ms

eu-west-1a, average round trip time = 96ms

This was based upon using http-ping to check the average round trip time of HTTP requests from our Ipswich development centre in the UK. So phew, the laws of physics still hold true even in a cloud world :)