HBM4 ramp: the race turns to supply
SK hynix began HBM4 shipments in Q2 and targets HBM4E production in 2027
The three lines
- SK hynix started HBM4 mass-production shipments in Q2 and signed long-term deals
- HBM4E samples went to major customers in the first half, with 2027 production targeted
- Samsung shipped HBM4 first in February; Micron passed $1bn in related revenue
Key questions
- When does HBM4 enter mass production
- It already has. Samsung shipped commercially in February, SK hynix began mass-production shipments in the second quarter and is expanding in the second half, and Micron has been ramping 12-high parts.
- What is HBM4E and when does it arrive
- The follow-on generation. SK hynix completed sample shipments to major customers in the first half and targets production in 2027; the specific quarter has not been disclosed.
- Who is winning the HBM4 race
- No one has won it. Samsung reached commercial shipment first, SK hynix has the broadest customer commitments, and Micron reports the fastest ramp relative to its own prior generation. The differentiator is now yield and supply capacity, not first silicon.
Every major memory supplier has now moved HBM4 into production, which changes what the competition is about. For two years the question was who could build it. From this quarter the question is who can hold yield while shipping volume, and that is a different contest with different winners.
1. Where each supplier stands
SK hynix said on its second-quarter call that HBM4 mass-production shipments began in the quarter, that second-half volumes will expand, and that long-term supply agreements are in place with roughly ten customers. The stock hit its daily limit on the news.
Samsung got there first in calendar terms, shipping commercial HBM4 in February and stating an intent to more than triple HBM revenue year over year.
Micron has framed its position in rate-of-change terms: its 12-high ramp is running at roughly twice the pace of its HBM3E ramp, with related revenue already past $1bn.
Three different claims, three different metrics — which is itself the point. No supplier is choosing to compete on the same axis.
2. The timeline
| Milestone | Supplier | Timing |
|---|---|---|
| First commercial HBM4 shipment | Samsung | February 2026 |
| Mass-production shipment begins | SK hynix | Q2 2026 |
| Second-half volume expansion | SK hynix | H2 2026 |
| Long-term agreements signed | SK hynix | about ten customers |
| HBM4E customer samples | SK hynix | H1 2026 |
| HBM4E production target | SK hynix | 2027 |
The gap between first shipment and volume shipment is where the money is. Being first to ship a qualified part matters for design wins; being able to supply that part at yield decides revenue. Accelerator makers commit a year or more ahead, so the supplier that can guarantee volume takes the socket even if it was second to qualify.
3. What is still open
The HBM4E production quarter has not been disclosed. The company target is 2027, and market talk of an accelerated schedule is not confirmed by anything the company has said.
Contract detail is thinner than the headlines suggest. Official material refers to about ten customers; some reports say eleven with five-year terms. Volume and pricing are not public in any of them. Micron has published nothing on HBM4E timing at all. The technical differences that make this generation matter — the doubled interface and the logic base die — are covered in a companion piece published the same day.