Why is HBM supply still constrained despite HBM4E samples?
Samples are not the same as uncommitted production capacity. Micron said its entire 2026 HBM supply was covered by price-and-volume agreements and later said it had contracted the vast majority of its 2027 HBM bit supply. The HBM4 redesign delayed the industry ramp, while Samsung and SK hynix shipping HBM4E samples marked a customer-sampling stage rather than broad volume availability. Micron targets HBM4E volume production in 2027, and SK hynix’s Indiana packaging plant is planned to begin next-generation HBM mass production in the second half of 2029. Buyers should therefore distinguish samples, qualified volume shipments, contracted supply, and future capacity additions when assessing availability.
Trace the chain
- 1Micron samples HBM4 for a 2026 rampAnnouncement
Micron ships HBM4 36GB 12-high samples, plans the ramp for calendar 2026
Micron announced shipment of HBM4 36GB 12-high samples to multiple key customers and said it planned to ramp HBM4 in calendar 2026 in line with customers' next-generation AI platforms.
Micron Investor Relations ·
Micron plans to ramp HBM4 in calendar year 2026, aligned to the ramp of customers' next-generation AI platforms.
Why it matters here. Micron’s HBM4 samples showed that its ramp was still planned for 2026; Micron subsequently said its entire 2026 HBM supply was covered by price-and-volume agreements.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 22026 Micron supply is contractedFinancial
Micron completes 2026 HBM price-and-volume agreements
Micron said it had completed price-and-volume agreements for its entire calendar-2026 HBM supply. The agreements included its HBM4 supply.
The Motley Fool (Micron Q1 FY2026 earnings call transcript) ·
We have completed agreements on price and volume for our entire calendar 2026 HBM supply, including Micron's industry-leading HBM4.
Why it matters here. Micron said agreements covered its entire 2026 HBM supply, while TrendForce reported that revised Nvidia requirements had delayed HBM4 mass production.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 4Samsung begins HBM4 commercial shipmentsLaunch
Samsung begins HBM4 mass production and commercial shipments, expects HBM sales to more than triple in 2026
Samsung announced mass production and commercial shipment of HBM4 running at 11.7 Gbps and capable of up to 13 Gbps, on a 4nm logic base die, and said it expected its HBM sales to more than triple in 2026 while expanding HBM4 capacity. It was Samsung's first claim of an HBM generation lead over SK hynix.
Samsung Semiconductor ·
Samsung anticipates that its HBM sales will more than triple in 2026 compared to 2025, and is proactively expanding its HBM4 production capacity.
Why it matters here. Samsung’s commercial HBM4 shipments added supply from one vendor, while Micron separately announced that it had entered HBM4 volume shipment.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 5Micron enters Vera Rubin volume shipmentLaunch
Micron in volume shipment of HBM4 for Nvidia Vera Rubin
Micron said it had begun volume shipment of HBM4 36GB 12-high in the first quarter of calendar 2026, designed for Nvidia's Vera Rubin platform, with a 2048-bit interface above 11 Gbps and more than 2.8 TB/s per stack.
Micron Investor Relations ·
Micron Technology, Inc. (Nasdaq: MU), has begun volume shipment of its HBM4 36GB 12H in the first quarter of calendar year 2026
Why it matters here. Micron’s HBM4 volume shipment showed the HBM4 ramp progressing, while Samsung’s following HBM4E announcement remained a customer-sample milestone.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 6Samsung moves HBM4E into samplingAnnouncement
Samsung ships the first 12-layer HBM4E samples at up to 16 Gbps
Samsung said it had begun shipping 12-layer HBM4E samples to major customers, reaching up to 16 Gbps with better energy efficiency and thermals, extending its roadmap after the HBM4 mass production earlier in the year.
Samsung Semiconductor ·
Samsung Electronics, a global leader in advanced memory technology, today announced that it has begun shipping the industry’s first 12-layer HBM4E samples to major global customers, further strengthening its leadership…
Why it matters here. Samsung reaching HBM4E samples moved the next generation from roadmap to customer hands, and SK hynix matched it within weeks.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 7SK hynix also samples HBM4EShipment
SK hynix ships 12-layer HBM4E samples to major customers
SK hynix announced that it had shipped HBM4E samples to major customers. The samples were for a 12-layer HBM4E product.
SK hynix ·
SK hynix announced today that it has shipped samples of HBM4E, a next-generation DRAM for AI, to major customers.
Why it matters here. SK hynix’s customer samples showed HBM4E had reached the sampling stage, while Micron still expected HBM4E volume production only in 2027.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 8Micron targets 2027 HBM4E volumeFinancial
Micron expects HBM4E volume production in 2027
Micron said development of HBM4E using 1-gamma DRAM technology was underway. The company said it expected volume production in calendar 2027.
Micron ·
Development of HBM4E, built on 1-gamma DRAM technology, is well underway, with volume production expected in calendar 2027.
Why it matters here. Micron expected HBM4E volume production in 2027, while SK hynix’s Indiana plant was not scheduled to begin next-generation HBM mass production until the second half of 2029.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
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- 10Most 2027 supply is contractedFinancial
Micron contracts most of its 2027 HBM bit supply
Micron said it had completed agreements for the vast majority of its calendar-2027 HBM bit supply, with significant year-over-year price increases that narrow the gross-margin gap with conventional DRAM.
Micron Technology, Inc. ·
We have completed agreements for the vast majority of our calendar 2027 HBM bit supply with significant price increases year over year, narrowing the gross margin gap with conventional DRAM.
Why it matters here. Micron’s agreements showed that its HBM supply commitments extended into 2027.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
What pushes back
- 3The HBM4 ramp is delayed
TrendForce: HBM4 mass production slips to the end of the first quarter of 2026 after Nvidia raised the spec
TrendForce said HBM4 mass production was now expected no earlier than the end of the first quarter of 2026, because Nvidia had revised the HBM4 specification for Rubin in the third quarter of 2025 to a per-pin speed above 11 Gbps, forcing all three suppliers to modify designs, and because strong Blackwell demand led Nvidia to adjust the Rubin production timeline.
TrendForce ·
Nvidia has revised the HBM4 specifications for its Rubin platform in 3Q25, raising the required per-pin speed to above 11 Gbps. This change has necessitated that the three major HBM suppliers modify their designs.
What it pushes against. Nvidia’s revised HBM4 requirement delayed the expected production start, before Samsung announced HBM4 mass production and commercial shipments.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 9Indiana packaging production moves to 2029
SK hynix breaks ground on the Indiana HBM packaging plant, now over US$4 billion with production in 2029
SK hynix held the groundbreaking ceremony for its West Lafayette, Indiana advanced packaging plant at Purdue University. The expected investment rose to over US$4 billion, the cleanroom is due by October 2028 and mass production of next-generation HBM in the second half of 2029, a year later than the 2028 target given in April 2024.
SK hynix Newsroom ·
The Indiana fab, with a total expected investment of over $4 billion, is scheduled to open its cleanroom by October 2028 and initiate mass production of next-generation HBM in the second half of 2029.
What it pushes against. SK hynix’s delayed packaging-plant production date puts a major future capacity addition later than originally planned.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
Changes to this chain
- Proposal #186 accepted (publish:hbm-memory-supply): insert after 9: [cause] Most 2027 supply is contracted -> hbm-memory-supply#1760: Micron’s agreements showed that its HBM supply commitments extended into 2027.; answer: Samples are not the same as uncommitted production capacity. Micron said its entire 2026 HBM supply was covered by price-and-volume agreements and later said it had contracted the vast majority of its 2027 HBM bit supply. The HBM4 redesign delayed the industry ramp, while Samsung and SK hynix shipping HBM4E samples marked a customer-sampling stage rather than broad volume availability. Micron targets HBM4E volume production in 2027, and SK hynix’s Indiana packaging plant is planned to begin next-generation HBM mass production in the second half of 2029. Buyers should therefore distinguish samples, qualified volume shipments, contracted supply, and future capacity additions when assessing availability.
- Step 6 why edited by the editor: Bridge to the next step instead of restating the entry
- Proposal #6 accepted (verify:v1): why of step 1 -> Micron’s HBM4 samples showed that its ramp was still planned for 2026; Micron subsequently said its entire 2026 HBM supply was covered by price-and-volume agreements.; why of step 2 -> Micron said agreements covered its entire 2026 HBM supply, while TrendForce reported that revised Nvidia requirements had delayed HBM4 mass production.; why of step 3 -> Nvidia’s revised HBM4 requirement delayed the expected production start, before Samsung announced HBM4 mass production and commercial shipments.; why of step 4 -> Samsung’s commercial HBM4 shipments added supply from one vendor, while Micron separately announced that it had entered HBM4 volume shipment.; why of step 5 -> Micron’s HBM4 volume shipment showed the HBM4 ramp progressing, while Samsung’s following HBM4E announcement remained a customer-sample milestone.; why of step 6 -> Samsung’s HBM4E customer samples were followed by SK hynix shipping 12-layer HBM4E samples to major customers.; why of step 7 -> SK hynix’s customer samples showed HBM4E had reached the sampling stage, while Micron still expected HBM4E volume production only in 2027.; why of step 8 -> Micron expected HBM4E volume production in 2027, while SK hynix’s Indiana plant was not scheduled to begin next-generation HBM mass production until the second half of 2029.
Timelines in this chain
- HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- Custom AI Silicon at the Hyperscalers: TPU, Trainium, Maia, MTIA and the OpenAI–Broadcom Chip
- GeForce and DLSS: From the RTX 50 Launch to 3D-Guided Neural Rendering
- Nvidia Data Center GPUs: Hopper, Blackwell and Vera Rubin
A chain is written by the editor from entries already published on the timelines above, each of which was read against its source before publication. The chain changes when those entries do. Data and terms.