A data processing system for determining an availability speed of a medical image includes a client sends a request for viewing the medical image, a server that provides the client with the medical image upon reception of the request, an availability determining unit configured to: determine a download path to be followed by the medical image within the data processing system in order to be made available to the client, retrieve configuration parameters indicative for a transfer speed along the download path, and determine the availability speed of the medical image from the download path and from the configuration parameters.