Marvell demos longer AI copper cable

Inside an artificial intelligence rack, the shortest cables can decide how many processors fit in the box. Marvell and Luxshare-Tech just showed a copper cable at the Optical Fiber Communication Conference 2026 that stretches a 200 gigabit-per-second lane connection to 2.5 meters instead of the usual 2 meters for this class of cable. (marvell.com) These links are the data-center version of the cords behind a TV stand, except each one carries traffic between servers and the top-of-rack switch. Marvell said copper is still the default for short runs because operators use it for roughly 0 to 5 meter server-to-switch links and because it is cheaper and simpler than optics at that distance. (prnewswire.com) A passive copper cable is just wire, like an extension cord with no electronics helping the signal along. Marvell says those direct-attach copper cables are hitting their limits as data centers move from 100 gigabits per second per lane to 200 gigabits per second per lane. (marvell.com; prnewswire.com) One fix is an active copper cable, which adds a tiny signal booster inside the cable. Marvell says this kind of cable usually reaches 2 to 2.5 meters and a 1.6 terabit active copper cable can run at about 2.5 watts, which keeps power low inside a packed rack. (marvell.com) Another fix is an active electrical cable, which uses a more capable digital signal processor at the ends, like putting a smarter repeater on the line. Marvell says that buys much longer reach of about 4 to 9 meters, but it also adds more power draw and more latency than active copper cables. (marvell.com; marvell.com) The new demo mixes those two ideas in one cable instead of choosing one. Marvell says the switch end uses a 1.6 terabit digital signal processor for active electrical cable, while the network-card side uses two 4-by-200 gigabit active copper redrivers on separate strands. (marvell.com) That layout matters because artificial intelligence racks often split one big switch port into many smaller device links. Marvell’s prototype used a Y-cable that connects one 8-by-200 gigabit top-of-rack switch port to two 4-by-200 gigabit network interface card links, which lets one cable assembly fan out to multiple endpoints. (marvell.com) The trade is simple: give up the 4 to 9 meter reach of a full active electrical cable, but keep more of the low power and low cost profile of active copper. Marvell says the hybrid reached 2.5 meters with thin 30 American Wire Gauge copper, which is 25 percent farther than an equivalent 2 meter active-copper-only design. (marvell.com) Thin wire sounds like a small detail, but it changes how a rack gets built. Marvell says the 30 American Wire Gauge design improves bend flexibility and thermal management, which means easier routing through dense trays where hundreds of cables compete for the same air and space. (marvell.com) Marvell also said the prototype hit a bit error rate of 1e-9 at a mid-range equalization setting, which is a lab way of saying the longer copper run still delivered clean enough signals to be taken seriously. The company said partners are already working on 3 meter and 4 meter versions, which would push copper a little farther before operators have to jump to optics. (marvell.com) That is the lane Marvell is trying to own: copper for the shortest and cheapest links, optics for the longest and biggest clusters, and hybrids in the awkward middle. In January 2025, Marvell said co-packaged optics can spread artificial intelligence scale-up fabrics from tens of processors in one rack to hundreds across multiple racks, so this new cable fills the gap before that optical handoff. (prnewswire.com; marvell.com)