ECC matters
ECC is required on mission critical hardware.<p>I have spent 36 years fielding embedded devices in core network (D1/E1, SONET, ROADM/MPLS, Cellular basestation) and I will tell you that large ECC covered memory arrays always show small numbers of correctable error events over the course of a year. I have seen, over the course of my career, exactly one controller card replaced early in the field, because it started throwing excessive recoverable ECC events over time, until it hit a threshold of 10x the average of a typical board. On the order of ten recoverable ECC events per  month instead of one event per month. I have never observed a logged non-correctable ECC event in the field. In the lab, yes, but never in fielded equipment.<p>If you are fine with your PC experiencing one or two bits flipped in memory every month, then you really don't need ECC. That is the question you need to answer.<p>For mission critical systems? ECC is a requirement.