Graphics can consume significant bandwidth and result in noticeable network delay. You can increase effective bandwidth by changing your graphics format to reduce the size of graphics files. Different graphics formats use different methods of encoding the data. Try different formats for your graphics, and choose the format that produces the smallest file size.
For example, the Joint Photographic Experts Group (JPEG) format usually produces the smallest file for a photograph. Graphic Interchange Format (GIF) usually produces the smallest file for a computer-generated graphic.
In summary, maintaining adequate bandwidth is a primary concern on Internet Information Server. You can use Performance Monitor and Network Monitor to monitor different aspects of bandwidth. If your data analysis reveals that bandwidth is insufficient, you can increase the bandwidth available to the server or tune some of the parameters that affect bandwidth and network capacity. Also, if you are administering a multipurpose server, consider limiting the bandwidth available to the IIS services to maintain a minimum bandwidth for other services.