Chrome became very resource hungry and poor at memory management recently. Sometimes I see half blank pages when scrolling which I've never seen before on the desktop.
Chrome may be inefficient with memory but I could manage this by closing the tab. Firefox would retain the memory even after the tab has been closed for some time.
Firefox is a lot better these days.
Lets say you have 200 tabs open, check your computers memory usage, close all of the tabs but one and see how much your memory usage drops. Then close that last tab (or fully quit the program on a mac), and see how much memory you get back.
I typically get about 1/4-1/2 of my total RAM back after closing the program entirely.
When rendering can't keep up with your rate of scrolling, Chrome will display the part that has been rendered so far and display a checkerboard pattern for the not yet rendered part. Previously, Chrome would just flip the display buffers less often if rendering can't keep up.