Samsung's HBM4: 80% yield, 3x revenue, 38% share

Samsung is reported to have lifted its HBM4 yield to 80%. When mass production began this February the figure was still under 60%, so this is a six-month change.

Samsung Cracks HBM4 Yields, Set to Overtake SK hynix Next Year (Seoul Economic Daily, 2026-08-10)

출처: en.sedaily.com

The same report says the next generation, HBM4E, cleared a 70% yield in reliability testing, and that 12-layer samples went out to customers in May. A target set for year-end arrived four months early.

Why yield turns into money so directly

HBM is DRAM stacked in layers and placed right beside the GPU. If a single layer in the stack goes wrong the whole stack is scrapped, so a fab with a low yield and one with a high yield get a different number of sellable parts out of the same wafers.

And prices happen to be climbing, which carries that difference straight through to revenue.

On July 30 Samsung told investors that third-quarter HBM4 revenue would more than triple from the prior quarter and that HBM4 would account for over 60% of total HBM revenue in the second half. That is the company's own plan, not an independently verified figure.

Between 21% and 39%

The target relayed in the original post is to lift HBM share to the level of the company's DRAM share by year-end. How far apart those two numbers sit today is the point of this card.

Across DRAM as a whole, Q2 2026 share was Samsung 39%, SK Hynix 26% and Micron 25%. The order flips only in HBM.

Vera Rubin allocation decides it

Yield is a number a company can move inside its own fab. Share is not. It is set by how many parts a customer assigns to whom.

Samsung and SK Hynix picked as HBM4 suppliers for Nvidia's Vera Rubin (KED Global, 2026-03-08)

출처: kedglobal.com

Back in March Nvidia chose Samsung and SK Hynix as the HBM4 suppliers for its next-generation Vera Rubin platform. That means both walked through the same door, not that both carry the same volume. The UBS estimate carried in the same Seoul Economic Daily piece has SK Hynix ahead at 48% in 2026, with the two drawing level at 41% and 39% in 2027. There is a year of daylight between the year-end the company describes and the next year outsiders model. What closes that year is not the fab but the contract. HBM4 price negotiations open in the fourth quarter, and the allocations settled there produce the year-end share. Above 35% and the DRAM-level position the company described has been reached; below it, this was the year the yield was fixed while the seating stayed the same.