If it starts dropping to 90fps I really notice a difference in my ability to perform as well. 120fps is what my max is set to, but I used to play at 250fps, so I'm a spoiled brat.
Higher than 70 ping and you start to notice issues with being able to block as easily (and playing on EU servers with 150 ping, if you're not blocking immediately after they start to chamber their swing, you won't block in time).
Graphics never mattered to me in Warband (so that's why I don't get any of the "enhancement" add-ons, like the heirloom pack, default ftw).