Why did the HBM4 industry ramp slip into 2026?

9 steps from 2025 to 2026 · 1 timelines · updated Oct 12, 2026 · version 6

Edited by Ceniy Mei · How chains are made

The answer, in one paragraph

HBM4 development was advancing through samples, the published JEDEC standard, and SK hynix’s September 2025 readiness claim, but Nvidia then raised its required per-pin speed above 11 Gbps. TrendForce said that change required redesigns and moved the expected industry start to no earlier than the end of the first quarter of 2026. Samsung began commercial shipments in February, Micron reported volume shipments in the first quarter, and reports placed Micron’s 12-layer mass production and SK hynix’s mass shipments in the second quarter. For scheduling, use the reported commercial, volume and mass shipment or production dates rather than development or readiness announcements.

Trace the chain

The argument runs in 2 strands, in the order the answer makes them, not by date; inside a strand the steps run forward in time, and a closing section lists what pushes against the answer. Each step is a dated entry with its source.

1Early HBM4 customer samplesMar 19, 2025Announcement
SK hynix ships the first 12-layer HBM4 samples, targets mass-production readiness in the second half of 2025
SK hynix said it had shipped 12-layer HBM4 samples to major customers, the first supplier to do so, and aimed to complete mass-production preparations within the second half of 2025.
SK hynix Newsroom · SK hynix aims to complete preparations for mass production of 12-layer HBM4 products within the second half of the year.
Why it matters here. SK hynix’s customer samples preceded JEDEC’s publication of the formal HBM4 standard in April.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
2Published technical baselineApr 16, 2025Announcement
JEDEC publishes the HBM4 standard, doubling channels per stack to 32
JEDEC released JESD270-4, the HBM4 standard, which doubles independent channels per stack from 16 to 32 with two pseudo-channels each, keeps backward compatibility with HBM3 controllers and adds directed refresh management. SK hynix, AMD, Synopsys and Cadence gave statements.
JEDEC · Doubled Channels: HBM4 doubles the number of independent channels per stack, from 16 channels (HBM3) to 32 channels with 2 pseudo-channels per channel.
Why it matters here. JEDEC’s published HBM4 specification set the technical baseline before Micron shipped its own 12-high HBM4 samples to customers.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
3Micron follows with samplesJun 10, 2025Announcement
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 customer samples, alongside SK hynix’s development effort, preceded SK hynix’s September declaration that its HBM4 mass-production system was ready.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
4SK hynix declares readinessSep 12, 2025Announcement
SK hynix completes HBM4 development and says its mass-production system is ready
SK hynix announced it had completed HBM4 development and finished preparing mass production, the first supplier to claim both, on the schedule it set in March.
SK hynix Newsroom · SK hynix Inc. announced today that it has completed development and finished preparation of HBM4, a next generation memory product for ultra-high performance AI, mass production for the world's first time.
Why it matters here. Although SK hynix said its HBM4 development and mass-production preparations were complete, TrendForce later reported that Nvidia’s revised requirement forced suppliers to modify their designs and delayed expected industry mass production.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
6Samsung ships in the revised windowFeb 12, 2026Launch
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 reported mass production and commercial HBM4 shipments in February, before Micron reported volume shipment in the first quarter.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
7Micron reports volume shipmentMar 16, 2026Launch
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 reported first-quarter volume shipment of HBM4 for Nvidia Vera Rubin, before SK hynix reported beginning its own mass shipments in the second quarter.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
8SK hynix reports later mass shipmentsJul 29, 2026Shipment
SK hynix says it began mass shipments of HBM4 in Q2 2026
SK hynix said it began mass shipments of HBM4 in the second quarter of 2026. It said it would ramp production in the second half of the year.
SK hynix · The company began mass shipments of HBM4 in the second quarter and will ramp up production in the second half of the year.
Why it matters here. SK hynix reported beginning HBM4 mass shipments in Q2 2026, while Electronic Times also reported Micron began 12-layer HBM4 mass production in that quarter.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E

Supplier ramp

9Micron mass production followsSep 4, 2026Report
Electronic Times reports Micron began 12-layer HBM4 mass production in Q2
Electronic Times reported that Micron began mass production of 12-layer HBM4 products in the second quarter of 2026. The report identified the products as 12-layer HBM4. The same report said Micron plans to add up to 60,000 wafers a month of HBM capacity by the end of 2026.
Electronic Times · Micron began mass production of 12-layer HBM4 products in the second quarter of this year.
Why it matters here. Electronic Times reported that Micron began mass production of 12-layer HBM4 products in Q2 2026, a production milestone distinct from earlier sample and readiness announcements.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E

What pushes back

Entries that count against the answer as a whole, not against the step before them.

5Nvidia raises the speed requirementJan 8, 2026
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 above-11-Gbps requirement forced all three suppliers to redesign and pushed expected mass production back; Samsung then shipped inside that revised window, at 11.7 Gbps.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E

Changes to this chain

Sep 19, 2026Step 5 why edited by the editor: Rewritten to lead to the next step rather than restate the entry.
Sep 19, 2026Proposal #132 accepted (verify:v4): why of step 5 -> TrendForce said Nvidia's above-11-Gbps Rubin requirement forced all three major HBM suppliers to modify their designs and moved expected HBM4 mass production to no earlier than the end of Q1 2026.
Sep 18, 2026Proposal #123 accepted (verify:v3): why of step 8 -> SK hynix reported beginning HBM4 mass shipments in Q2 2026, while Electronic Times also reported Micron began 12-layer HBM4 mass production in that quarter.; why of step 9 -> Electronic Times reported that Micron began mass production of 12-layer HBM4 products in Q2 2026, a production milestone distinct from earlier sample and readiness announcements.
Sep 18, 2026Proposal #119 accepted (publish:hyperscaler-custom-accelerators): insert after 8: [cause] Micron mass production follows -> hbm-memory-supply#769: This adds a reported second-quarter 2026 Micron mass-production date to the comparison of actual supplier-ramp milestones.; answer: HBM4 development was advancing through samples, the published JEDEC standard, and SK hynix’s September 2025 readiness claim, but Nvidia then raised its required per-pin speed above 11 Gbps. TrendForce said that change required redesigns and moved the expected industry start to no earlier than the end of the first quarter of 2026. Samsung began commercial shipments in February, Micron reported volume shipments in the first quarter, and reports placed Micron’s 12-layer mass production and SK hynix’s mass shipments in the second quarter. For scheduling, use the reported commercial, volume and mass shipment or production dates rather than development or readiness announcements.
Sep 15, 2026Proposal #7 accepted (verify:v1): why of step 1 -> SK hynix’s customer samples preceded JEDEC’s publication of the formal HBM4 standard in April.; why of step 2 -> JEDEC’s published HBM4 specification set the technical baseline before Micron shipped its own 12-high HBM4 samples to customers.; why of step 3 -> Micron’s customer samples, alongside SK hynix’s development effort, preceded SK hynix’s September declaration that its HBM4 mass-production system was ready.; why of step 4 -> Although SK hynix said its HBM4 development and mass-production preparations were complete, TrendForce later reported that Nvidia’s revised requirement forced suppliers to modify their designs and delayed expected industry mass production.; why of step 6 -> Samsung reported mass production and commercial HBM4 shipments in February, before Micron reported volume shipment in the first quarter.; why of step 7 -> Micron reported first-quarter volume shipment of HBM4 for Nvidia Vera Rubin, before SK hynix reported beginning its own mass shipments in the second quarter.

Timelines in this chain

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.