There might be a few reasons. 1. Your internet provider could be the problem. Sometimes my internet provider (Comcast) decreases the signal in my area. 2. Your computer could be too loaded with garbage. Do a "disk defragment" and a "disk cleanup" (Windows). Also delete other stuff not being used like emptying your trash icon and deleting email messages you've sent. 3. I've noticed that when a hub is especially large it takes longer to load up. Normally this is in the Forum section.
It's likely that computer memory is not the issue. So clean up your hard drive first and see what happens.