DDR5: The New Generation of Memory Standard

What is DDR5 SDRAM?

DDR5 SDRAM is the final specification (JESD79-5) of the next-generation mainstream memory standard, which opened the prelude to a new era of global computer memory technology. JEDEC describes DDR5 as a "revolutionary" memory architecture and believes that its emergence marks the transition of the entire industry to DDR5 server dual in-line memory modules (DIMMs).

According to market research organization Omdia, the market demand for DDR5 will gradually appear from 2020. By 2022, DDR5 will occupy 10% of the entire DRAM market, and will further expand to 43% in 2024. Yole Development predicts that the widespread adoption of DDR5 should begin in the server market in 2022. In 2023, mainstream markets such as mobile phones, laptops, and PCs will begin to adopt DDR5.

The driving force behind DDR5

The growth rate of memory bandwidth is far behind the increase in processor performance, which is the fundamental driving force behind the launch of DDR5. For example, from 2000 to 2019, the memory bandwidth rapidly increased from about 1GB/s to 200GB/s, but at the same time, the number of processor cores also increased from the early single-core and dual-core to the current maximum of more than 60 cores in a system. In such a system with ultra-multi-core processors, the available bandwidth allocated to each processor core is seriously insufficient, and the call for increasing DRAM bandwidth is increasing.

From the perspective of the application side, the popularity of DDR5 has also been pressed by the "accelerator key." The main reasons are: ①The rapid growth of PCs, tablets, and servers. ②The demand for low latency, low power consumption, high speed, and large bandwidth in the edge computing and AI era. ③Supports from head manufacturers such as AMD/Intel/Hynix/Samsung.

Data center

In which applications will DDR5 appear first? We generally believe that it will follow the pace of DDR4 and be the first to be introduced into the data center. The iterations of its previous generations of products are prioritized in PCs.

This trend accelerates the iteration of DDR to a new generation of faster and more efficient products. Major manufacturers have deployed DDR5 memory and promoted its extensive commercialization. According to a report by the China Securities Research Institute, as far as the global DRAM memory market is concerned, servers will consume 34% of the global DRAM memory usage in 2020. The amount of DRAM memory used in servers is expected to increase by nearly 40% year-on-year in 2021, and exceed 50% of the overall DRAM usage in 2024.

PC and tablet

Research institute Canalys announced the first quarter global computer market report on May 5, 2021: The global computer market shipments increased by 53.1% year-on-year to 122.1 million units. Among them, Google Chromebook grew the most, with shipments of 12 million units, a year-on-year increase of 274.6%. In addition, tablet PCs grew by 51.7%, with shipments of 39.7 million units.

The shipment of PCs and tablets has skyrocketed, and the demand for DDR memory has also increased significantly. DDR5 has begun to be introduced to the market. TrendForce predicts that the market share of DDR5 in the PC DRAM market will grow from less than 1% in 2020 to 10% in 2021, showing a growth rate of more than 10 times.

However, it is worth noting that because PC consumers are extremely sensitive to the price of the whole machine, and the price of DDR5 at the initial launch has a higher premium compared with DDR4. Intel only supports DDR5 memory on the Alder Lake platform of its newly launched 12th-generation Core processor, while AMD is expected to select all systems to support DDR5 memory in the Zen 4 platform launched in 2022.

Edge computing

The main goal of many edge computing applications is to revolve around new services related to lower latency. In order to support lower latency, many new systems have adopted some of the latest industry interface standards, including PCIe 5.0, LPDDR5, DDR5, HBM2E, USB 3.2, CXL, PCIe-based NVMe, and other technologies based on next-generation standards. Compared with previous generation products, each of these technologies reduces latency through bandwidth improvements.

At the same time, AI algorithms are breaking through the limits of memory bandwidth requirements. Obviously, it not only requires high-capacity memory to support these needs but also requires many complex applications to be executed in the edge cloud. In order to support the realization of this capability, it is not a surprise that designers adopt DDR5 in the new chipset.

What is the value of DDR5?

Before answering this question, you should obviously understand the relationship between DDR4 and DDR5.

Comparison of some features between DDR4 and DDR5. Source: Comprehensive data from JEDEC and technology media Anandtech

DDR memory can send and receive data signals twice in one clock cycle, which is twice the rate of DRAM produced in the 1970s, 1980s, and 1990s. DDR4 is the fourth-generation DDR SDRAM released in the second half of 2014. Although DDR5 is the fifth generation, it has changed a lot from the upgrade iterations of DDR2, 3, and 4. The iterative focus of previous generations of products is mainly focused on how to reduce power consumption. Mobile and terminal applications are the main driving forces; while the main driving factor of DDR5 is the increasing number of new processor cores, resulting in existing Memory bandwidth can't keep up with the rhythm, and the demand for bandwidth must be further increased.

The core value of DDR5 SDRAM is mainly reflected in the following four aspects:

1. Higher speed, lower voltage

The most eye-catching part of DDR5 is that it is faster than the already "super fast" DDR4. Compared with the maximum transmission speed of DDR4 memory of 3.2Gbps under 1.6GHz clock frequency, the maximum transmission rate of the new DDR5 memory has reached 6.4Gbps. In addition, DDR5 has also improved the operating voltage of the DIMM, reducing the power supply voltage from 1.2V of DDR4 to 1.1V, further improving the energy efficiency of the memory.

2. Higher memory density

DDR4 only supports up to 16Gb of DRAM capacity in single die package (SDP) mode, while the DDR5 memory standard increases this number to 64Gb. This means that the maximum capacity of DDR5 DIMM in SDP mode can reach 256GB, which is 4 times the maximum capacity of DDR4 64Gb. At the same time, DDR5 also supports a stack of up to 40 units, which can make its effective memory capacity reach 2TB.

3. Updated power supply and channel architecture

DDR5 DIMM transfers the power management from the motherboard to the memory module itself and ensures a more refined system power load through an onboard 12V power management chip. The burst length of each channel is doubled from 8 bytes (BL8) to 16 bytes (BL16). In terms of pin design, DDR5 memory will maintain the same number of 288 pins as DDR4, but due to different definitions, it is not compatible with DDR4 slots.

4. Higher frequency and refresh

According to JEDEC, the pin bandwidth (frequency) of DDR5 memory is twice that of DDR4, and the total transmission bandwidth can be increased by 38%. The starting frequency of 4800MHz is also 50% higher than that of DDR4 3200MHz. However, this is only the beginning. In the future, the highest frequency of DDR5 memory is even expected to reach 8400MHz, and the system bandwidth will continue to increase to more than twice the current level.

DDR5 core players' plan

Statistics show that DRAM chips account for 19% of China's integrated circuit market in 2020. The three major manufacturers, including Samsung, SK Hynix and Micron, produce approximately 86% of the world's DRAM wafers and contribute 95% of the global DRAM industry's revenue. Their latest developments will undoubtedly become the vane of the DDR5 market.

SK Hynix

After SK Hynix successfully developed the world’s first 16Gb DDR5 DRAM in November 2018, it provided samples to core customers such as Intel, and completed a series of tests, performance, and compatibility verification procedures, which means that SK Hynix can sell related products at any time in the coming DDR5 market. Later in October 2020, SK Hynix announced the launch of the world's first DDR5 DRAM module. If combined with through-silicon via (TSV) technology, high-capacity modules with a capacity of up to 256GB can be formed.

The data transfer rate of DDR5 DRAM launched by SK Hynix is up to 4,800-5,600Mbps, which is up to 1.8 times higher than the previous generation DDR4. The transfer rate of 5,600Mbps means that 9 full high definitions (FHD) movies can be transferred in 1 second. Not only that, the working voltage of this product has been reduced from 1.2V of the previous generation to 1.1V, successfully reducing power consumption by 20%.

Micron

Micron launched the DDR5 Technology Enablement Program (TEP) in 2020. The plan aims to accelerate the market's adoption of DDR5 and prepare the ecosystem for the widespread use of DDR5-enabled platforms in 2022. At present, the plan has attracted more than 250 design and technology leaders from more than 100 industry leaders, including system and chip service providers, channel partners, cloud service providers, and original equipment manufacturers.

As shown in the figure below, compared to 3200MHz DDR4, the same 3200MHz DDR5 can provide 1.36 times more efficient bandwidth. However, Raj Hazra, Micron Technology's senior vice president and general manager of the Computing and Networking Division, emphasized that the launch of DDR5 will not happen overnight, and it needs the strong support of the ecosystem.

Micron DDR5

"Compared with 5 years ago, the current data center storage system is more complex, covering various forms such as packaged memory, HVN/high-bandwidth memory, DDR4/DDR5, CXL. Through these open methods, we can now integrate memory and computing together. Through the hierarchical division of near memory and far memory, data center innovation can be achieved.” Raj Hazra said this is essential for scaling AI applications because huge AI models processing must be modular and expandable, so that memory and storage technology must not only be able to disperse processing, but also achieve aggregation when necessary.

Samsung

At the HotChips 33 conference in 2021, Samsung announced its first and the industry's first single 512GB DDR5 memory module with a frequency of 7200MHz. According to the information released by Samsung, the 512GB single DDR5 memory module displayed this time uses Samsung's 8H stacked TSV technology, which achieves a smaller volume through the eight-layer stack. Compared with Samsung's previous 4H TSV technology DDR4 memory stick, it can reduce the gap between chips by nearly 40%.

Samsung DDR5

Samsung believes that the short-term demand of consumer users will not exceed 64GB. Even after upgrading to DDR5 content, the demand of consumer users should be around 64GB. According to Samsung’s expectations, mainstream market demand will not transition to DDR5 memory until 2023-2024. Before this time, DDR4 will still be the mainstream in the market.

TrendForce's research data also confirmed this judgment. According to the deals that have been drawn up, the quarterly increase in the average price of mainstream modules DDR4 1G*8 2666Mbps is close to 25%, exceeding the original market expectation by 20%. The price increase of Server DRAM, which is highly related, has also expanded simultaneously. In addition, the prices of DDR3, DDR4, mobile DRAM, and graphics DRAM are all rising, pushing the overall average DRAM price increase in the second quarter of this year by 18~23%.