For gaming, 24 Mbps is overkill, at least 6 times over, if not 60. Where this gets less certain is when you are using steam-based games, which are constantly downloading content in advance of you playing that "segment" of the game.
Where a higher bandwidth connection is going to be a requirement is going to be when someone decides to do something peer to peer, and or if someone wants to stream music or video, while you are playing.
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