This is actually an old question that I asked in the chatroom but got no satisfied solution.
I can't remember when this began to happen, probably not from the very beginning, but when I noticed, I had been waiting for my computer's reviving everyday for a minute or so when I visited Mathematica.SE for the first time that day.
I admit I've already got used to this, I've developed the habit to drink a cup of water and so on to kill the time, but today I suddenly sobered up: I should ask this formally in meta, to make sure if there is really no way to relieve this, or to draw more attention to this issue if it's currently incurable.
I use Vista 32bit, Chrome 40, on an old 2GHz dual core laptop with 2GB memory. The problem appeared at least from Chrome 25.
Oleksandr R. mentioned that he suffered the same issue in the chat room. Don't tell me we're the only two!