As of today, many datacenters, particularly those operated by hyperscalers like Google, Facebook, Microsoft, and Amazon, embrace the 48V power architecture as a more efficient alternative to the older 12V systems. This shift marks a significant evolution in datacenter power infrastructure, driven by the need for increased efficiency, reduced power losses, and better support for the high-performance workloads that define modern computing environments.

The Decline of 12V Power Architecture in Datacenters

Historically, datacenters relied on a 12V power distribution architecture, which became widely adopted due to its simplicity and compatibility with early server designs. However, as datacenters have scaled to meet the demands of cloud computing, artificial intelligence (AI), machine learning, and other data-intensive applications, the limitations of 12V systems are becoming increasingly apparent. One of the main issues is that delivering higher amounts of power using 12V results in a significant current, which leads to power losses due to resistance (P = I²R) in the distribution network.

In addition to these power losses, 12V systems require multiple conversion steps to reduce the voltage to the levels needed by modern CPUs, memory, and other server components. Each conversion step introduces inefficiency, making it increasingly difficult to meet the energy demands of hyperscale datacenters while maintaining acceptable operational costs.

Why 48V Power Architecture is Now Prevalent

The shift from 12V to 48V power architecture is now a widely adopted strategy in hyperscale datacenters, driven by its superior efficiency, scalability, and adaptability to modern workloads. By increasing the voltage to 48V, datacenters can reduce the current required to deliver the same amount of power, which significantly reduces power losses due to resistance in cables and connectors​(48v-rack-power-architec…). This makes 48V systems far more efficient than their 12V counterparts.

1. Lower Power Losses

One of the most significant advantages of 48V systems is the drastic reduction in power distribution losses. Power losses in a conductor are proportional to the square of the current, meaning that higher voltages reduce these losses dramatically. In a 48V system, this translates into up to 16x lower distribution losses than a 12V system​. This is a crucial factor for hyperscale datacenters, which must manage power distribution efficiently across thousands of servers.

2. Fewer Conversion Steps

In a traditional 12V system, power is converted multiple times before it reaches the components that use it. First, AC power is converted to 12V DC, then to lower voltages required by CPUs, memory, and other components. These multiple conversions introduce inefficiencies at each step. In contrast, 48V systems reduce the number of conversion steps, with power being directly converted from 48V to the lower voltages required at the point of load (PoL). This not only improves efficiency but also simplifies the power distribution infrastructure.

3. Support for High-Demand Workloads

Modern datacenters increasingly rely on high-performance computing resources, such as GPUs, FPGAs, and specialized accelerators, which require significantly more power than traditional CPU workloads. The 48V architecture is better suited for delivering the large amounts of power needed by these components without suffering from excessive power losses. The use of 48V-to-PoL regulators ensures efficient power delivery to CPUs, memory, and accelerators, enabling datacenters to handle more demanding applications​.

4. Improved Scalability and Flexibility

As datacenters continue to scale to meet the needs of growing cloud services and AI workloads, 48V systems offer better scalability than 12V systems. The higher voltage allows for more compact and efficient designs, reducing the size and cost of power distribution components, such as cables, connectors, and busbars​. This makes it easier for hyperscalers to deploy large-scale infrastructure while minimizing space and energy costs.

Google’s Leadership and Contribution to 48V Adoption

Google has played a pivotal role in the widespread adoption of 48V power architecture, contributing to the development of standardized 48V systems through the Open Compute Project (OCP). In 2016, Google introduced a 48V rack power architecture designed to replace traditional 12V systems, marking a major shift in datacenter design. Google’s 48V system was developed to meet the power demands of modern high-performance computing, particularly in applications requiring GPUs and other power-hungry accelerators.

One of the key innovations in Google’s 48V architecture is the 48V-to-PoL voltage regulator, which allows direct conversion from 48V to the lower voltages required by CPUs and memory. This design eliminates the need for multiple conversion steps, significantly improving efficiency and reducing power losses. Google reported a 30% reduction in conversion losses and a 16x reduction in distribution losses compared to 12V systems.

In addition, Google’s 48V architecture utilizes busbars to distribute power within the datacenter racks. These busbars replace traditional power cables, allowing for more efficient and reliable power distribution. By eliminating individual power supply units (PSUs) in each server, Google’s system reduces the complexity of power management and improves reliability, as fewer components are needed to manage power delivery​(External-2018-OCP-Summi…).

The Rise of 48V as the Industry Standard

Today, 48V power architecture is becoming the standard for hyperscale data centers. Companies like Facebook, Microsoft, and Amazon, in addition to Google, have adopted 48V systems to meet their growing power needs while reducing energy consumption and improving operational efficiency. This transition is being driven by the need to handle more power-hungry applications, such as AI and machine learning while minimizing energy costs and environmental impact​.

Furthermore, the development of more efficient 48V-to-PoL regulators and other components has made it easier for datacenters to adopt 48V systems. As the 48V ecosystem continues to mature, with contributions from companies like Google and advances in power conversion technologies, it is expected that 48V systems will become even more efficient and scalable.

Challenges of Power Supply Design for 48V Systems

While the benefits of 48V power supplies are clear, the transition to this architecture is not without challenges. Designing a reliable and efficient power supply for 48V systems requires careful consideration of several factors, including compatibility with existing infrastructure and the selection of appropriate power supply components.

Single-Stage vs. Two-Stage Power Conversion

One of the key challenges in implementing 48V power systems is the choice between single-stage and two-stage power conversion. In a single-stage system, power is directly converted from 48V to the lower voltages required by server components. This approach offers the advantage of a smaller power supply circuit, which is particularly beneficial in space-constrained environments. However, it also limits the selection of usable circuits and components, which can drive up costs.

In contrast, the two-stage method involves first converting 48V to an intermediate voltage and then stepping it down to the final load voltage. While this approach requires a larger power supply circuit, it offers greater flexibility in component selection and is compatible with existing 12V infrastructure. This makes the two-stage method more practical during the early stages of transitioning to 48V systems​.

Component Selection and Bulk Capacitors

Another critical aspect of 48V power supply design is the selection of components, particularly capacitors. Bulk capacitors are essential for stabilizing the power supply and ensuring reliable operation. In a two-stage power supply, high-performance capacitors are required to handle the large current fluctuations that occur during load changes. Panasonic’s conductive high-polymer capacitors, for example, are well-suited for this role, offering long life, high ripple current capacity, and reliability under varying temperatures.

The choice of capacitors can significantly impact the performance and reliability of the power supply. For instance, aluminium electrolytic capacitors provide a cost-effective solution but may suffer from temperature-related degradation over time. Hybrid capacitors, which combine solid and liquid electrolytes, offer a middle ground between cost and performance, making them a popular choice for 48V systems.

Drawbacks and Future Outlook

Despite its advantages, the transition to 48V systems does come with drawbacks. One of the primary challenges is the cost associated with new components and infrastructure. Although 48V systems are more efficient in the long run, the initial investment in new power supplies, busbars, and cooling systems can be significant. Additionally, there are compatibility issues with existing 12V servers, which may require expensive retrofitting or replacement to integrate with 48V architectures​.

Looking ahead, as more datacenters transition to 48V power systems, further innovations in power supply design will be required. The development of more compact and efficient 48V-to-PoL regulators, as well as advances in capacitor technology, will play a key role in ensuring the widespread adoption of 48V systems. Furthermore, as demand for high-performance computing continues to grow, 48V architectures will become increasingly essential in managing the power and thermal challenges of modern data centers.

In conclusion, the transition to 48V power systems in datacenters is a crucial development driven by the increasing power demands of modern processors and the need for greater efficiency in large-scale computing environments. With advantages such as significantly reduced power losses, better scalability, and improved thermal management, 48V systems have become essential for supporting the high-performance workloads of today’s datacenters, particularly in the context of 5G, AI, and cloud computing. However, the shift to 48V power architecture also presents challenges, particularly in terms of cost, compatibility with existing infrastructure, and power supply design. The choice between single-stage and two-stage power conversion, as well as the careful selection of components like bulk capacitors, will play a critical role in optimizing the performance and reliability of 48V systems. Despite the hurdles, the benefits of 48V power architecture are clear, positioning it as the new industry standard for efficient and sustainable datacenter operations.

About Wired and Wireless Technologies (WAWT)

WAWT (Wired and Wireless Technologies), a strategic technology analyst and consultancy firm, specializes in the wireless power and power supply industry. Its comprehensive research and reports on the power supply industry, titled “AC-DC and DC-DC Merchant Power Supply Market Report” and “External Power Adapters and Chargers Market Report”, offer critical market data, trends, insights and market intelligence. It provides the latest market size estimates and forecasts for the power supply market, benefiting companies across the power supply ecosystem. The report analyses the market across various segments – by product; application sector (including servers, storage, networking, datacentres, telecom, medical, industrial, lighting, railways, etc); region; power class and others; and includes a detailed competitive analysis of power supply vendors looking at their market share. Furthermore, it ranks all profiles of power supply companies based on their revenues, across industry sectors, including datacentres.

WAWT‘s report is an invaluable resource for businesses seeking to understand the power supply landscape, make informed decisions, and stay competitive in this dynamic industry.

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