Different size but not different design. Specifics for the I/O die were never fully disclosed, but the design is supposedly in identical quadrants with 2 memory channels and 2 chiplets connected to each. 1 of those layouts would be for the Matisse die, 4 of those would be the Rome die. Would Threadripper 3 have 2 quadrants or all 4?The EPYC does get a different cIOd chiplet right now.