When using the sync feature for the first time you can choose a server location, with options such as Amazon hosted servers in California (USA), London (UK), Japan and a server in China, we recommend choosing the server closest to you for faster upload and download speeds.
You can also change the server location later:
Swipe down from the top of the screen to bring up the top status bar and tap the "Settings" icon.
Tap "Security & privacy" then "Server location".
Select a location and tap “Change”.