I switched back from Chrome to Safari (for totally unrelated reasons) between the last time I had this problem and the current time. Maybe Chrome is better about throttling background tabs these days (and better than Safari). Also, this time, wikis and strategy pages seem to load fine (though noticeably slower), but it's a little too hard for me to order a pizza on Grubhub, especially if I'm context switching back and forth between the browser and the game. All I can actually say with confidence is that I have run into a performance bottleneck well before hitting the single-thread will-it-run-at-all barrier.