Since its inception, the SD memory card has been the unassuming hero of our digital lives. Largely unseen but quintessential, it has stored our precious memories, saved our vital data, and provided an indispensable level of flexibility and security. These removable cards have become emblematic of our advancing technological capabilities, largely due to innovation and adaptability to the ever-changing landscape.

Five years after the introduction and evolution of the SD Express standards, the market has seen one groundbreaking innovation after another, changing what is possible in the world of data storage, processing and how products are designed. 

The Beginnings of SD Express

In 2018, the tech world was abuzz when the SD Association (SDA) announced the SD Express standard. This revolutionary standard built upon the existing SD interface, integrated the PCIe® interface and NVMe™ protocol to enable faster data transfer rates, making it ideal for handling data intensive applications and transferring ultra large data files. 

This represented a huge evolutionary step. The tiniest, most popular removable memory card form factors in the world—SD and microSD—now supported PCIe/NVMe interfaces and were granted a huge increase in performance, from 10 to up to 40 times faster than UHS-I.

The introduction was more than just about rapid data transfer; it was a symbolic step marking the seamless integration of storage and processing technologies—pushing boundaries on what removable memory cards could do. 

Highlighting the Advancements: A Version-by-Version Dissection

The SD Express specification has seen several iterations, each amplifying what its predecessor achieved. Let’s do a quick review of each version’s contribution:

  • Version 7.0: June of 2018 saw the SDA release its foundational SD Express version, integrating the PCI Express (PCIe Gen 3.1) and NVMe interfaces to SD memory cards, promising speeds of up to 985 MB/s. This new protocol allowed SD Express memory cards to serve as removable Solid State Drives (SSD). 
  • Version 7.1: In February of 2019, the SD 7.1 specification expanded SD Express features to the microSD memory card. microSD Express incorporates the SD Express interface, comprised of the PCle 3.1 and NVMe interface with the legacy SD interface. 
  • Version 8.0: In March 2020, SD 8.0 specification was launched. It offered the fastest SD Express capabilities to date, delivering gigabyte speeds via dual PCIe lane support and PCIe Gen 4.0 with NVMe on a full size SD Express card. This version provided enhancements and increased the performance capability to a staggering ~4GB/s (3,938MB/s). 
  • Version 9.0: In May 2022, SD9.0 introduced new optional features for SD memory cards enabling it to better serve as semi-embedded memory or applications where the card needs to be tightly bound to a specific host device. The Fast Boot and Secure Boot features give cards the ability to serve as a device’s boot code memory; Replay Protected Memory Block (RPMB), which offers a secured hidden memory accessible only through a secured authentication process and provides a replay protection security mechanism (e.g. for secured Boot code updates); and TCG Storage – A secured storage method defined by the Trusted Computing Group (e.g. for  a self-encrypted drive function). This innovative approach allows SD memory cards to replace embedded memory and make repairs and upgrades on devices easier than ever before or enabling cards to be tightly bound to specific hosts.
  • Version 9.1: October 2023 saw introduction of new SD Express Speed Classes 150, 300, 450, and 600, further refining the standards, ensuring minimum sequential performance through its PCIe/NVMe interface along with a support for multi-stream recording and new features that allowed optimized Power and Thermal Management control while assuring the minimum speed class performance.
  • microSD Addendum v8.0: In October 2023 the microSD Express memory card doubled its maximum speed up to 2GB/s via the single lane PCIe Gen 4.0 interface.

Each subsequent release layered new storage opportunities on top of the existing structure, preparing and evolving SD Express for the emerging storage demands of future applications.

The Resounding Impact of Innovation

SD Express is not just about faster data transfer; it’s about building a bridge to the future. The technology is an ecosystem player, influencing key trends in the industry. The next generation SDUC capacity specification exceeds the SDXC 2TB max capacity specification barrier, allowing for an almost the-sky-is-the-limit max capacity of 128TB. This level of card capacity puts SD Express at the forefront of managing and maximizing large quantities of data.

As storage capacities continue to soar, peak transfer speeds will continue to keep pace and break records. This is more than simply interesting statistics – it’s a revolutionary development that brings intense data-reliant activities, like filmmaking or surveillance, to a striking new level. SD Express has played a pivotal role in redefining consumer device capabilities, with a special potential in consumer and professional products and solutions such as gaming consoles, cameras (video, still, action, 360o, dash), IoT, drones, mobile computing and even mobile phones.

Adapting to Right-to-Repair Laws

In a world that is amassing an alarming amounts of electronic waste, SD Express shines a light on an increasingly critical role – that of a component that can extend a device’s lifespan and help product manufacturers to comply with growing right-to-repair laws. With its features, SD memory cards can be used as semi-embedded, replaceable storage, enabling manufacturers to comply with the regulatory environment and promote the reuse and refurbishment of electronic devices.

Amplifying Market Presence: A Glimpse of the Now

While some aspects of SD Express may be seen as theoretical, such as the maximum 4 GB/sec speeds, SD Express is far from a concept observed only in labs. Major companies have developed, or are in the process of developing, products that harness the potential of this technology. The momentum is building and will only continue to grow. The following is a list with links to a few examples:

We can see a diverse array of products starting to utilize SD Express, all benefiting from the rapid data access that was once only a domain of internal storage or bulky peripherals.

The Need for Speed: Future Applications That Rely on SD Express

The need for speed is more acute than ever, and SD Express is not just keeping pace; it’s sprinting ahead, setting new specifications of rapid data access. In fields like drones and action cameras, a matter of milliseconds can make a difference. In gaming, it’s a requisite for fluid gameplay. And in the burgeoning field of AI at the edge, the swiftness of data transactions can mean the difference between a system that learns efficiently and one that lags behind.

The uses are diverse, but the demand for speed is a constant. And as we gear up for a future where such applications become more prevalent, SD Express stands as a vital enabler, a dependable companion in our quest for unparalleled technological advancement.

The Trailblazing Journey Continues

In the five years since its introduction, SD Express has demonstrated remarkable innovation. It has evolved from a novel concept to a ubiquitous feature, from a standalone component to an enabler of larger industry trends. The promised speed and efficiency bring us closer to a world without boundaries, where data is not a constraint but a passport to endless possibilities.

As we note this milestone, it’s clear that the journey of SD Express is far from over. With every new advancement, it cements itself as a linchpin in the mechanisms that drive our hyper-connected world. The next five years will undoubtedly bring more testing, development and exciting opportunities, but one thing remains certain: the legacy of SD Express will endure, influencing the technology we use and, more importantly, the lives we lead.