n an interview for HPCwire, Professor Thomas Sterling says that MRAM is one of the most promising material expected to replace silicon for supercomputing chip production. From the interview: "The most likely replacement for silicon is silicon; and by that I mean new semiconductor materials incorporating silicon. Beyond that, my personal opinion is that the most promising technologies likely to enhance the use of advanced silicon technologies are: a) chip to chip optical interconnects, b) Wafer-scale technology, but this has to have built-in fault tolerance, otherwise low yields will kill it. c) Niobium RSFQ super-conductive technology; this is unpopular, but the power benefits at higher clock rates are significant. And d) MRAM - magnetic RAM for low power, high density storage. There is also the possibility of new packaging techniques that may greatly increase density, such as 3-D structures; but this assumes we can get the heat out. In each of these cases we have enough proof of concept experiments in laboratory tests to demonstrate their promise Using fiber optics one can deliver close to one Terabit per second rates and super-conductive material can clock at in excess of 700 GHz. RSFQ was cited in a previous ITRS report by the SIA as a potential future technology.