3Mb? Dang, that's a quite fast I2C, particularly via a B2B-connector or whatever they use. Where from you got that 3Mb figure? And 3Mbps/8 = 375kBps (w/o overhead for protocol) if my math isn't weak. Doesn't sound like a too decent framerate to me (like 1fps on a 8bit grayscale 800*480), but then... e-ink probably has low res and low bpp