[Post-HBM Start] ③ New Markets Open with CXL... Samsung and SK Signal Launch with New Products

Samsung Electronics and SK Hynix, leaders in the development of High Bandwidth Memory (HBM), are expected to launch the ‘Compute Express Link (CXL)’ market as early as this year. This is a ‘next-generation memory’ technology that is attracting attention for its potential to complement and replace the shortcomings of HBM in the future.

CXL has similar functions and roles to HBM, such as improving the performance of memory required for computation. However, its method is more efficient and less expensive. While HBM stacks multiple DRAM chips vertically to increase bandwidth and boost computation speed, CXL expands memory capacity simply by adding modules, thereby accelerating computation. It has the advantage of being able to gather the central processing unit (CPU) and GPU memory semiconductors needed for data computation in one place, and it is evaluated as capable of handling the large amounts of data required by recently developed generative AI. Experts describe CXL as “a technology that significantly expands the road connecting the brain-like CPU and memory semiconductors from a single lane to ten lanes.”

Samsung Electronics announced that it held a briefing session on July 18 under the theme "Samsung Electronics CXL Solution." The photo shows an image of the CXL product. Photo by Samsung Electronics [Image source=Yonhap News]

Industry insiders predict that the release of CXL products will signal the dawn of the ‘post-HBM’ era. If CXL demonstrates sufficient potential, the use of HBM is expected to gradually decline. Subsequently, evolved DRAMs capable of performing ‘chiplet’ and computation functions are expected to emerge one after another, potentially replacing HBM in all aspects including functionality, influence, and performance, leading the semiconductor market into a new phase.

Samsung and SK Preparing for CXL

Samsung Electronics and SK Hynix, who have been fiercely competing to accelerate HBM development, have quietly been preparing for CXL behind the scenes. Both companies are expected to release their results within this year.

According to industry sources on the 23rd, Samsung Electronics is pushing to mass-produce the 256-gigabyte (GB) module CMM-D based on CXL 2.0 version in the second half of this year. Samsung, which had lost the lead to SK Hynix in HBM, is said to have been determined to make a comeback with CXL. It has been focusing on developing CXL for over 10 years. During this process, it has achieved visible results. In 2019, it formed the CXL consortium with NVIDIA, AMD, and others, and in May 2022, it developed the world’s first CXL DRAM based on CXL 1.1 version. Last year, Samsung released a 128GB CXL DRAM supporting version 2.0. SK Hynix is also focusing on developing ‘96GB and 128GB CXL 2.0 memory solution products’ based on DDR5, aiming for mass production in the second half of this year. The global market research firm Yole Intelligence forecasted that the CXL market, which was worth $1.7 million (about 2.2 billion KRW) in 2022, will grow to about $15 billion (about 20 trillion KRW) by 2028.

SK Hynix announced in August 2022 that it developed a memory sample based on 'Compute Express Link' (CXL), known as the next-generation DRAM. The photo shows an image of the CXL DRAM developed by SK Hynix. Photo by SK Hynix [Image source=Yonhap News]

Attention on Chiplets and PIM

Besides CXL, the industry is also focusing on ‘chiplets’ as a technology to replace HBM and succeed it. Chiplets refer to combining semiconductors with different functions into a single product. It is a ‘packaging’ technology that enables multiple semiconductors to perform tasks individually handled by separate chips. This reduces the burden on global companies that had to pay large costs to supply many semiconductors. Because of this, chiplets are expected to become products boasting the best cost-effectiveness.

Canadian semiconductor fabless startup Tenstorrent plans to launch an AI chiplet called ‘Quasar’ next year. There is also growing interest in whether newly developed DRAMs can replace HBM functions. Companies are also drawing attention for their efforts to equip AI chips with low-power DRAM (LPDDR) or graphics DRAM (GDDR6) as alternatives to HBM. Expectations are also high for Processing In Memory (PIM). PIM is a DRAM that processes some of the computation functions performed by processors such as CPUs and GPUs inside the memory itself. However, currently, it is perceived not as a separate technology to replace HBM but rather as a technology that partially assists HBM’s functions to enhance performance.

Not Giving Up HBM Leadership

The preparations to pioneer new markets are aimed at preparing for the post-HBM era. Samsung Electronics and SK Hynix have no reason to give up their leadership while HBM still exerts strong influence. SK Hynix will participate in the ‘Open Innovation Platform (OIP) Forum’ hosted by Taiwan’s TSMC, the world’s largest foundry (semiconductor contract manufacturing) company, at the Santa Clara Convention Center in California, USA, on the 25th. At this event, SK Hynix will present ‘2.5D system-in-package for improving HBM quality and reliability.’ SK Hynix has been jointly researching this with TSMC. They will also set up a booth on-site and exhibit 5th generation HBM, HBM3E, LPCAMM2, and GDDR7.

Samsung Electronics is promoting HBM innovation by combining foundry and system LSI technologies. Lee Jung-bae, head of the Memory Business Division, formalized this in a keynote speech at ‘Semicon Taiwan 2024’ held earlier this month in Taipei, Taiwan. It is also reported that the 6th generation HBM4 will begin mass production next year using the 4-nanometer (nm; one billionth of a meter) foundry process.