Do I really need the "Source Code" in my repository list?

Solution 1:

Unless you are planning to modify the software yourself then you can safely disable it. Most users will never need the source code.

You can shut it off by launching the Software Center, then going to Edit -> Software Sources in the menu, and then disabling the "Source Code" check box:

It will then prompt you for your password and then rerun an update.

Solution 2:

This does not specifically address the question about whether or not you need to have source code repositories enabled. But you may find it useful, as it directly addresses the most common cause of the slowdown you're having. I copied this from my answer here.

You can have the update manager select the best main repos to use automatically, which will result in the best download speeds. To do that, open Update Manager, then click Settings. Select the Ubuntu Software tab, then in the "Download from:" dropdown, select Other...

Now, in the window that pops up, click "Select Best Server"

It will then perform several tests to select the best server for you. Once it is completed, just click Choose Server.

Now, just run your updates again and you should notice an improvement (if your best available repo wasn't already selected).