Inconsistent file download speeds from Salesforce due to distance

Ultimately, when it comes to download speeds, data will be delivered slower as the round trip latency (distance traveled) increases. For Salesforce, your files are not geographically hosted as they are in a Content Delivery Network (CDN) - rather they are stored in a single Data Center in the US. For example, someone located in Los Angeles downloading a file from NA14 in Washington D.C. will see lower download speeds than someone located in Boston downloading the same file. With a CDN, files are mirrored and hosted geographically so that users can download the file from the closest location to them. 

Salesforce optimizes its network, app servers and database servers to provide an optimal experience across all of its functionality, and as a result we may be slower in specific situations (e.g., file downloads) versus single function services like Dropbox. 

There are options to integrate Salesforce with CDNs, such as Amazon S3 (Simple Storage Service) for example, for static resource caching depending on what type of files need to be stored and served. Please check out this link for more information relating to Amazon Web Services: https://www.salesforce.com/customer-success-stories/aws/

In regard to implementation of a CDN, Salesforce will never store client data on a CDN automatically. We do utilize CDNs for static resources, but in the purpose of Trust we will not house client data on third party servers.

Real-Life Scenario: An APAC-based user downloading large files from a Salesforce instance hosted in the US notices significantly slower speeds compared to their US colleagues. This is expected — Salesforce stores files in a single US data center rather than distributing them via a Content Delivery Network (CDN). This article explains why this happens and what options are available.

Upload Speeds Note:

Although most documentation discusses the improvement of download speeds thanks to CDN's, a Content Delivery Network may also benefit file upload speeds, for these two reasons:

• A CDN will tend to have a better backhaul network than going over the public internet - so bandwidth will be better overall. 
• If there are connection issues in the network path, these would happen between the client and the CDN POP (usually quite close), instead of connection issues between a client and a server across the ocean or across the country.