Meta reuses old RAM in new servers with custom bridge chip

Meta developed a custom CXL chip called Vistara to reuse older RAM from decommissioned servers in new machines, addressing rising memory prices and a surplus of older DIMMs. The approach decouples older memory via a CXL interface, enabling cost-effective performance without significant degradation. This innovation helps Meta manage server memory constraints amid a market where RAM prices could double by 2026.

The would-be AI infrastructure provider aims to solve the problem of rising memory prices in a cost-effective way. With the cost of new RAM soaring, Meta has found a thrifty way to reuse older memory in newer servers. The performance of about 40% of Meta’s millions of servers is limited by a lack of memory, the company said — but it has a surplus of older DIMMs from decommissioned servers, because RAM chips can last about twice as long as the rest of the machine. To profit from this imbalance, it developed a custom Computer Express Link CXL chip it calls Vistara, and associated software, to decouple older memory from server memory channels, enabling its reuse in new machines alongside their native memory. Using the older RAM with the CXL interface doesn’t significantly affect performance — although it would have done if the older DIMMs were plugged straight into newer servers. Kudos to tech site The Register https://www.theregister.com/systems/2026/06/29/zuck-saves-meta-bucks-by-reusing-memory-from-old-servers-with-a-custom-cxl-asic/5263483 for noticing the development, which Meta described in a technical paper: Vistara: Making CXL Real — Full Path from ASIC Design and OS Support to Hyperscale Deployment,” setting out how the new technology works https://aisystemcodesign.github.io/papers/isca26/vistara camera ready.pdf . There is a particular need to be thrifty right now, given the current state of the market. Last year, users were warned that memory prices could double https://www.networkworld.com/article/4093752/server-memory-prices-could-double-by-2026-as-ai-demand-strains-supply.html by the end of 2026, while the RAM shortage could last until 2027 https://www.computerworld.com/article/4161043/the-memory-shortage-appears-set-to-continue-through-2027.html . This week, Apple suggested using cheap Chinese chips https://www.networkworld.com/article/4192382/cheap-chinese-chips-could-offer-way-out-of-ram-price-crisis-apple-suggests.html , a move that may well be frowned on by the Trump administration. The Meta development may prove to be an efficient way forward.