eInk displays have 85-90Hz refresh rate. Just look up the datasheets.
Though it does not mean the same thing it does for LCD displays. It just means you can stuff raw data to the display at that rate. Pixels are sticky so you're either driving them towards white or black or not at all (individually). And you may need to drive them multiple times (or for different periods of time), to get the correct shade of gray, or whatever.
So you still need several full scans to perform what user would think of as a screen update.
Though it does not mean the same thing it does for LCD displays. It just means you can stuff raw data to the display at that rate. Pixels are sticky so you're either driving them towards white or black or not at all (individually). And you may need to drive them multiple times (or for different periods of time), to get the correct shade of gray, or whatever.
So you still need several full scans to perform what user would think of as a screen update.