Why did SK hynix take the lead in the HBM memory supply race?
By being first to the next generation’s samples and by holding the shipment share — not by having the field to itself. Micron was already in volume production of 24GB HBM3E for Nvidia's H200 in February 2024 and Samsung had announced a 12-high 36GB part the next day, so SK hynix's HBM3E volume production from late March 2024 entered a contested market. Where it pulled ahead was the next generation: it shipped the first 12-layer HBM4 samples to major customers in March 2025, a month before JEDEC published the standard that doubled independent channels per stack to 32, and in September 2025 it said it had completed HBM4 development and prepared mass production, the first supplier to claim both. Counterpoint put its second-quarter 2025 HBM shipment share at 62 percent against Samsung's 17 percent. What the same timeline does not show is a lead on HBM4 volume. TrendForce expected industry mass production no earlier than the end of the first quarter of 2026 after Nvidia revised the specification, and Samsung announced mass production and commercial shipment on 12 February 2026, ahead of that. Samsung shipped 12-layer HBM4E samples in May 2026; SK hynix shipped its own in June, and said its HBM4 mass shipments had begun in the second quarter.
Trace the chain
How SK hynix got ahead
- 3HBM3E volume supplyLaunch
SK hynix begins volume production of HBM3E, supplying a customer from late March
SK hynix said it had begun volume production of HBM3E for supply to a customer from late March 2024. It did not name the customer; the announcement came the day after Nvidia's GTC keynote.
SK hynix Newsroom ·
SK hynix Inc. announced today that it has begun volume production of HBM3E, the newest AI memory product with ultra-high performance, for supply to a customer from late March.
Why it matters here. Supplying a customer from late March 2024 put SK hynix into HBM3E volume production, the position it then tried to extend by being first to the next generation's samples.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 4First HBM4 samplesAnnouncement
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 was the first supplier to ship 12-layer HBM4 samples to major customers, targeting mass-production readiness in the second half of 2025, and did so a month before the next entry’s standard for the generation was published.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 5JEDEC sets HBM4Announcement
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. The published standard doubled independent channels per stack from 16 to 32, giving SK hynix a fixed target to complete development against.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 6Development completeAnnouncement
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. SK hynix said it had completed HBM4 development and prepared mass production; separately, Counterpoint later reported that it held 62 percent of Q2 HBM shipments, against Samsung's 17 percent.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 762 percent of shipmentsReport
Counterpoint reports SK hynix and Samsung held 79% of Q2 HBM shipments
Counterpoint Research reported that SK hynix held 62% and Samsung Electronics held 17% of global HBM shipment share in the second quarter of 2025. The reported combined share was about 79%.
Counterpoint Research ·
2025년 2분기 전세계 HBM 시장에서 SK하이닉스와 삼성전자가 출하량 기준 점유율 62%, 17%를 기록하며, 이로써 K-HBM이 전체 시장의 약 79% 차지
Why it matters here. Counterpoint measured SK hynix at 62 percent of second-quarter HBM shipments against Samsung's 17 percent, and the next entry's specification revision resets the timetable for the generation after it.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
What pushes back
- 1Micron ships HBM3E first
Micron starts volume production of HBM3E for Nvidia's H200
Micron said it had begun volume production of its 24GB 8-high HBM3E, which would ship inside Nvidia H200 GPUs from the second calendar quarter of 2024, making Micron a first-wave HBM3E supplier alongside SK hynix.
Micron Investor Relations ·
Micron's 24GB 8H HBM3E will be part of NVIDIA H200 Tensor Core GPUs, which will begin shipping in the second calendar quarter of 2024.
What it pushes against. Micron was already in volume production of 24GB HBM3E for shipment inside Nvidia H200 GPUs, which pushes against any account in which SK hynix began with the market to itself.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 2Samsung's 12-high part
Samsung develops the first 12-high 36GB HBM3E, mass production planned for the first half of 2024
Samsung announced HBM3E 12H, a 12-stack, 36GB part it called the highest-capacity HBM to date, said it had begun sampling to customers, and targeted mass production in the first half of 2024.
Samsung Semiconductor ·
Samsung has begun sampling its HBM3E 12H to customers and mass production is slated for the first half of this year.
What it pushes against. Samsung had announced a 12-stack 36GB HBM3E, begun customer sampling and targeted mass production in the first half of 2024, so the capacity race was under way before SK hynix shipped.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 8Nvidia's spec resets the clock
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. After Nvidia revised the HBM4 specification for Rubin, TrendForce expected industry mass production no earlier than the end of the first quarter of 2026, with all three major suppliers having to modify their designs — a date the next entry’s announcement arrives before.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 9Samsung gets to HBM4 volume first
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.
What it pushes against. Samsung announced HBM4 mass production and commercial shipment on 12 February 2026 at 11.7 Gbps, and the next entry shows it taking the following generation’s first sampling milestone as well.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 10Samsung samples HBM4E
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…
What it pushes against. Samsung's May 2026 shipment of the first 12-layer HBM4E samples at up to 16 Gbps preceded SK hynix's shipment of its own 12-layer HBM4E samples to major customers in June.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 11SK hynix samples HBM4E
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.
What it pushes against. SK hynix's June 2026 HBM4E samples do not themselves establish HBM4 volume leadership: the company said only that its HBM4 mass shipments had begun in Q2.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- 12HBM4 mass shipments
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.
What it pushes against. SK hynix said its HBM4 mass shipments began only in the second quarter of 2026, with the ramp still ahead in the second half, which qualifies any claim that its lead extended to HBM4 volume.
HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
Changes to this chain
- Proposal #360 rejected (verify:v8): superseded: the step and the answer were corrected by hand
- Step 7 why edited by the editor: the share Counterpoint reported is for HBM overall, not for one generation
- Proposal #349 accepted (verify:v7): why of step 6 -> SK hynix said it had completed HBM4 development and prepared mass production; separately, Counterpoint later reported that it held 62 percent of Q2 HBM shipments, against Samsung's 17 percent.; why of step 11 -> SK hynix's June 2026 HBM4E samples do not themselves establish HBM4 volume leadership: the company said only that its HBM4 mass shipments had begun in Q2.
- Proposal #231 rejected (verify:v6): Rewritten by hand: the conclusion is left to the later volume-shipment steps.
- Proposal #230 rejected (verify:v5): Step 7 is the last cause step handing into the counter strand, where a contrast is the correct relationship; verify itself calls it a relevant transition. Reworded to make the contrast explicit rather than implying causation.
- Proposal #229 rejected (verify:v4): Rewritten by hand to state the sequence without the requirement claim.
- Proposal #228 rejected (verify:v3): Both lines adopted verbatim in chains/why-sk-hynix-led-hbm-supply-race.yaml, which is this chain's source.
- Proposal #227 rejected (verify:v2): Rewritten by hand: the handoffs now use each step's own entry together with the next one.
- Proposal #226 rejected (verify:v1): Rewritten by hand in chains/why-sk-hynix-led-hbm-supply-race.yaml: the comparisons belong in the answer, which may synthesise across steps, not in why-lines, which may use only their own entry.
Timelines in this chain
- HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
- Nvidia Data Center GPUs: Hopper, Blackwell and Vera Rubin
- Custom AI Silicon at the Hyperscalers: TPU, Trainium, Maia, MTIA and the OpenAI–Broadcom Chip
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.