As the storage market is poised for a rebound, Samsung is also eager to make a move, preparing fully for the future.

According to the latest news, at the upcoming ISSCC conference, Samsung will not only showcase the astonishingly fast GDDR7 VRAM but also bring the high-speed next-generation 280-layer flash memory. At the same time, Samsung has recently disclosed the company's 3D DRAM plan.

Let's take a look at the latest progress of the storage giant.

NAND, 280 layers

At this year's ISSCC, Samsung hopes to launch the new type of NAND flash memory with the highest data density to date. It is understood that Samsung will share a presentation titled "A 280-Layer 1Tb 4b/cell 3D-NAND Flash Memory with a 28.5Gb/mm² Areal Density and a 3.2GB/s High-Speed IO Rate" at the time, revealing its next-generation V9 flash memory.

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As the title says, Samsung has developed a new generation of QLC NAND flash memory with 4 bits per cell, which is said to have an extremely high area density, reaching 28.5 Gbit per square millimeter. From this data, even SK Hynix's high-density TLC-NAND with more than 300 layers and 20.0 Gbit/mm² announced, as well as Intel's first PLC-NAND with 5 bits per cell and 23.3 Gbit/mm², are not as dense as Samsung's new memory.

According to a report from Samsung in 2022, Samsung has basically fully committed to the development of QLC. As the TLC flash memory architecture begins to reach the limit of the original storage capacity (just like SLC and MLC before), QLC represents the future of SSD manufacturers who hope to continuously break through the capacity limits of mainstream consumer SSDs. It may even enter the enterprise-level SSD in the future.

V9 is just the next step in Samsung's QLC roadmap. The speed of the next few generations of products should be faster than V9, and eventually, they can directly compete with today's upcoming TLC flash memory architecture in terms of raw performance.The speed of the V9 will not be slow either. According to reports, Samsung's V9 QLC has a maximum transfer rate of 3.2 Gbps. This is much faster than its upcoming QLC-based product that only provides 2.4 Gbps. In the past, speed has been a fundamental issue for QLC, and Samsung's new V9 NAND flash memory indicates that it has made significant progress in addressing this issue. The speed of V9 at 3.2 Gbps (per chip) should be more than enough for PCIe SSDs. Of course, how it performs in practice remains to be seen.

What is currently unclear is how performance will scale when written directly in QLC mode. All current QLC SSDs use a pSLC cache, which can be up to 25% of the total available capacity, significantly improving performance. Depending on the NAND, once the cache is full, we usually see a drop in write speeds to 100-300 MB/s.

If the performance is good enough, Samsung's new QLC-based flash memory will be available later this year, potentially fundamentally changing the consumer SSD landscape. QLC may still not be suitable for high-performance SSDs, such as those that support PCIe 5.0 transfer speeds, but it should be very suitable for lower-tier PCIe drives. With a storage density lead of nearly 50%, we can expect any new Samsung hard drives using the new V9 QLC flash memory to offer competitive value and possibly the most favorable price per GB in the industry.

According to market demand, Samsung may even offer V9 QLC M.2 hard drives with capacities exceeding 8TB, which is the highest capacity currently available in consumer M.2 hard drives. Samsung may even launch a single-sided 8TB hard drive.

In recent years, Samsung has repeatedly emphasized that QLC-NAND will continue to exist. So far, the slow write speed has been a fatal weakness, but there should also be progress in this area. High surface density first ensures one thing: reducing manufacturing costs, as the more bits installed on the wafer, the better.

GDDR7 VRAM: 37 Gbps

GDDR (i.e., Graphics Double Data Rate memory, initially called DDR SGRAM - double data rate synchronous graphics RAM) is another highlight of Samsung's display this time. The latest advancement in this technology is GDDR7, which Samsung first announced at the 2022 Technology Day.

In July 2023, Samsung said that the company has completed the development of the industry's first Graphics Double Data Rate 7 (GDDR7) DRAM. It will first be installed in key customers' next-generation systems for verification in the remaining time of that year, promoting the future growth of the graphics market and further consolidating Samsung's technological leadership in this field.

Samsung said that following the company's development of the industry's first 24Gbps GDDR6 DRAM in 2022, the company's 16 Gb GDDR7 product will provide the highest speed in the industry to date. Despite high-speed operation, innovations in integrated circuit (IC) design and packaging still provide higher stability."Our GDDR7 DRAM will help enhance the user experience in fields that require excellent graphics performance, such as workstations, PCs, and gaming consoles, and is expected to expand into future applications such as artificial intelligence, high-performance computing (HPC), and automotive," said Yongcheol Bae, Executive Vice President of Samsung Electronics' Memory Product Planning Team. "The next-generation graphics DRAM will be brought to market according to industry demand, and we plan to continue maintaining a leading position in this field."

Samsung further pointed out that GDDR7 has achieved an impressive bandwidth of 1.5 TBps, which is 1.4 times that of GDDR6's 1.1 TBps, and the speed per pin has been increased to up to 32 Gbps. These enhancements are achieved through the pulse amplitude modulation (PAM3) signaling method adopted by the new memory standard, rather than the non-return-to-zero (NRZ) signaling method of previous generations. PAM3 allows for 50% more data transmission than NRZ within the same signaling period.

It is worth noting that, as Samsung stated, the latest design has improved energy efficiency by 20% compared to GDDR6, through power-saving design techniques optimized for high-speed operation. For applications that pay particular attention to power consumption, such as laptops, Samsung offers a low operating voltage option.

To minimize heat generation, in addition to IC architecture optimization, Samsung has also adopted an epoxy molding compound (EMC) with high thermal conductivity in the packaging materials of the new generation of GDDR. As a result, these improvements have significantly reduced the thermal resistance of GDDR7 by 70% compared to GDDR6, helping to maintain stable product performance even under high-speed operation.

However, Samsung is not stopping there. At the upcoming five-day 2024 IEEE International Solid-State Circuits Conference in San Francisco in February, Samsung will bring a new GDDR7 showcase, where they will present a paper titled "A 16Gb 37 Gb/s GDDR7 DRAM with PAM3-Optimized TRX Equalization and ZQ Calibration." Although there are not many details, it can be seen from the title that Samsung has increased the speed of GDDR7 to 37 Gb/s.

GDDR7 memory will utilize both PAM3 and NRZ signals, aiming to achieve a data rate of up to 37 Gbps per pin. Its development involves increasing the signal transmission rate and burst size without significantly raising the internal clock of the memory cell. This allows each GDDR version to increase the memory bus frequency, thereby improving performance.

However, as frequency increases become complex, the industry is exploring other solutions. For example, GDDR6X replaced the traditional NRZ encoding with PAM4 encoding, effectively doubling the data transfer rate. PAM4 also significantly reduced signal loss due to the lower baud rate.

However, GDDR7 will utilize PAM3 encoding, which is a compromise between PAM4 and NRZ signals. This allows for a higher data transfer rate per cycle than NRZ, reducing the need for higher memory bus frequencies. GDDR7 promises better performance than GDDR6, as well as lower power consumption and implementation costs than GDDR6X.

Due to the adoption of PAM3 signaling instead of traditional signaling methods, GDDR7 VRAM is expected to not only see significant improvements in bandwidth but also in power consumption (at the same performance level as GDDR6/X). Of course, fully utilizing GDDR7 can still see it using power comparable to modern GDDR6 configurations, just with higher performance per watt. The next version of USB4 is also expected to adopt PAM3 signaling to reduce power consumption.In addition, GDDR7 also provides methods for optimizing memory efficiency and power consumption. This includes four different read clock modes, allowing it to operate only when necessary. The GDDR7 memory subsystem can also issue two independent commands in parallel, thereby optimizing power consumption.

As for its release, GDDR7 is expected to be launched alongside the next-generation GPUs from AMD and NVIDIA, likely later this year.

It is worth mentioning that two versions of GDDR7 VRAM are expected to appear at this year's ISSCC: the low-power 35.4 Gb/s per pin GDDR7 from SK hynix, and the higher-power 37 Gb/s per pin GDDR7 from Samsung. According to Micron, the bandwidth per pin of GDDR6X is approximately 19-24 Gigabits.

3D DRAM, a preview

In addition to NAND and GDDR, Samsung has also revealed the company's 3D DRAM layout.

3D DRAM is a storage chip with a new structure that breaks away from the current aging paradigm. The development of existing DRAM products focuses on improving integration by reducing circuit line width. However, as the line width enters the 10 nm range, physical limitations such as capacitor current leakage and interference significantly increase. To prevent this, new materials and equipment such as high-k dielectric deposition materials and extreme ultraviolet (EUV) equipment have been introduced. But the semiconductor industry believes that miniaturizing manufacturing of 10-nanometer or more advanced chips will pose a huge challenge for chip manufacturers.

It has been reported that Samsung Electronics has confirmed the establishment of a new next-generation memory research and development (R&D) organization to seize the 3D DRAM market, which is commonly referred to as "dream memory." According to industry insiders, Samsung Electronics Semiconductor (DS) has recently established a cutting-edge memory R&D institution at the Semiconductor America Headquarters (DSA) in Silicon Valley. The organization is led by Song Jae-hyeok, the Chief Technology Officer (CTO) of Samsung Electronics DS and the head of the Semiconductor Research Institute, and is committed to pioneering research on 3D DRAM.

3D DRAM is hailed as a "game-changer" in the memory semiconductor industry and has the potential to completely change the global DRAM market landscape. While current DRAM has a 2D structure with cells densely arranged on a single plane, 3D DRAM can significantly improve performance by increasing the density in the same area, either by horizontally placing cells and stacking them upwards or using a double-layer vertical approach.

With the experience of being the first in the world to commercialize 3D vertical structure NAND in 2013, Samsung Electronics also plans to bet on 3D in the DRAM field.

On March 10 last year, at the IEEE EDTM 2023 held at COEX in Seoul, Lee Jong-myung, Vice President of Samsung Electronics Semiconductor Research Center and head of the process development office, said, "3D DRAM is considered the growth engine of the semiconductor industry in the future." Cha Seon-yong, Vice President of SK hynix in charge of the Future Technology Research Institute of SK hynix, also said on March 8, 2023, "By next year (2024), details of the electrical characteristics of 3D DRAM will be announced, determining their direction of development."In October last year, at the 2023 Samsung Memory Technology Day held in Silicon Valley, the president of the memory business, Lee Jeong-bae, announced, "We will be the first to introduce a new 3D vertical structure in DRAM below 10 nanometers." They claim that the new structure of DRAM below 10 nanometers will allow the capacity of a single chip to exceed 100 GB.

Industry experts believe that the company that first develops and mass-produces 3D DRAM will take the lead in the next-generation DRAM market, echoing the layer competition in the NAND flash memory market.

The technological competition in the field of 3D DRAM is also intensifying. According to the semiconductor technology analysis company TechInsights, Micron, the third-ranked memory semiconductor market, is actively preparing for the blue ocean market and has obtained more than 30 3D DRAM patent technologies by August 2022. In contrast, Samsung only has 15 related patents in 3D DRAM, and SK Hynix has only about 10.

In addition to the above technologies, HBM is also a focus of Samsung, which is also an area that Micron and SK Hynix are heavily investing in.