Does leage require a lot of troughput?

I get very laggy when my internet signal degrades for some reason, no surprise there. But what i noticed is that i only get my maximum 60ms ping when my internet speed is about atleast 15 mbps, or more of course, and the lag increases as the speed goes down. At 2,5 mbps i had a surprising 1000ms ping. Is this normal behavior? Just how much troughput does leage needs to run smoothly?

A 720p youtube video eats 3mbps, while on the same speed playing leage on the lowest settings with shadows and everything turned off basicly is still unplayable. Is 10 characters jumping around on my screen, casting spells has become that big of a deal? I remember reading the graphics get "heavier" over time as the game gets rejuvenated .