Use the Show Threads selection to control how many posts you see. If you visit the site often, you might want to set it to 'active in the last week'. This will only show you posts that have been placed in the past week. The shorter the time period, the faster the sytem will display the posts.

You can change your Show Threads default in the Control Panel under "Display preferences, number of shown threads, languages, colors... ". You'll find a link to the Control Panel underneath the bones.