Facebook is one of the most prevalent websites on the Internet, available in dozens of languages with users from countries all around the world. In spite of its popularity, Facebook's website interface isn't simple, and some elements may cause your computer to run slowly while using Facebook.
Facebook Chat is also a memory and resource drain. Facebook Chat allows you to chat with multiple people at once. Although several chat conversations can appear within your Facebook window -- and display at the bottom of the website interface -- each of them constitutes an addition browser window that appears separately if you launch the Windows Task Manager. Having several chat sessions going at once can cause your computer to run slowly, in spite of Facebook's streamlined conversation interface.
Uploading Photos and Videos
Facebook allows you to open multiple instances of your session in different tabs and windows, so if you're uploading photos or videos to the site, you can continue browsing in another tab or window. In addition to the additional memory usage for opening a new window, Facebook's default uploader uses Flash, which is a resource-intensive.
Slow Internet Connection
You may simply have a slow Internet connection. Slow connections can cause your computer to run slowly while using Facebook, as your computer devotes more resources than normal to process the load request. This means that your computer will have less resources to devote to other applications and processes, which slows down overall performance.