Who makes retimers inside AECs for AI data centers

A passive copper cable works until the signal will not survive the run. A retimer inside the cable fixes that: it receives the degraded signal partway along, recovers the clock and data, and transmits a clean copy onward, which is what turns a direct-attach cable into an active electrical cable. The chip is in the connector housing at one or both ends, powered from the port. This part exists because of where it sits between two alternatives. Passive copper is cheaper and uses no power but runs out of reach as per-lane rates climb; optics goes much further but costs more per port and burns more power. AECs occupy the middle — long enough to cross a rack or reach an adjacent one, at a fraction of the power of an optical link — and every jump in lane rate shortens passive reach and widens that middle ground. AI racks are exactly the case that made it matter, because they concentrate a large number of very high-rate links inside and between a small number of cabinets, where the runs are short but no longer short enough to be passive. What to look for is which lane rates a retimer supports and whether it has been designed into a specific cable vendor's product, since these are sold to cable assemblers rather than to operators. Watch the reach boundary too: it moves with every generation and decides how much of the rack stays copper.