I measured the load speed of a static image file severed by nginx from my server (using pingdom service). The server should normally process this request within few seconds. My server is located in Dallas, TX. When I used pingdom Dallas server, it took 200ms to load the file. This includes DNS resolving, and data transfer. Obviously for longer transfer, it should takes longer; but surprisingly this value was 800ms for NYC and 1.5s for Amsterdam.
The apparent conclusion is the role of distance for data transfer from server to client machine, and nothing connected to my server performance. However, when I checked this difference for major websites such as google and bing; the difference was only 50% (e.g. 200ms for US and 300s for Europe).
Is there something to be improved in my server to server long-distance requests?