Memory expansion — more DRAM on one host — ships today: Microsoft Azure's M-series went to preview on Astera Labs controllers in February 2026, per the company's disclosure. Tiering runs in production at Meta, per a paper showing within 1% of an ideal baseline. Pooling, the 'break the memory wall' story, stays aspirational: the flagship study was an emulation, '100TB pools' are proofs-of-concept, no named generally-available multi-rack deployment exists. The research insists: underwrite what ships; treat pooling as a 2027-plus option.