NVIDIA Rubin said to stick with 12-layer HBM4 as HBM prices seen up 121% in 2027
A supply-chain survey cited by Counterpoint Research indicates most of NVIDIA's next-generation Rubin AI accelerators will keep the originally planned 12-layer HBM4 stacks, rather than shifting broadly to 8-layer HBM4 as earlier rumors suggested. NVIDIA's published roadmap lists 12-high HBM4 with up to 288GB of memory per GPU and bandwidth up to 22TB/s; Korean media had reported that NVIDIA asked Samsung Electronics and SK hynix for more 8-layer HBM4 supply, and industry observers say the two accounts need not conflict — some products may use 8-layer stacks to ease capacity pressure while flagship Rubin parts stay at 12 layers. Separately, TrendForce forecasts HBM average selling prices could rise 121% year over year by 2027, driven mainly by the mix shift from HBM3E to pricier HBM4 rather than pure shortage; because the costly base die is spread over fewer memory layers, 8-layer HBM could cost 10% to 20% more per Gb than 12-layer in 2027.
Memory capacity and bandwidth remain key to large-model training and inference performance, making HBM supply and pricing a central cost variable for next-generation AI infrastructure.