Large difference in results between London and Dublin

[davidrapson]

I was wondering if anyone could shed some light on why I would be getting such different results between the London and Dublin locations.

I completely appreciate that location would be expected to make a difference. But I didn't expect to see as much difference as I'm seeing given these are Geographically close together.

Some background:

• The server hosting the page being tested is in London
• Static assets are being hosted via CloudFront backed by an S3 bucket in Dublin
• Tests are both on Cable w/ 3 tests each
  

London: http://www.webpagetest.org/result/141120_8B_11NM/
SpeedIndex of 2148 on first run

Dublin: http://www.webpagetest.org/result/141120_R8_11NQ/
SpeedIndex of 928 First Run

Anyone know why these results would be so different?

Thanks,
David