What are the three types of PDUs?

The three main types of rack power distribution units (PDUs) are basic PDUs, metered PDUs, and switched PDUs. They differ in monitoring capabilities, remote control functions, and ideal use cases: basic models deliver simple power distribution, metered units add real-time load visibility, and switched PDUs enable remote outlet-level control. As rack power density grows, organizations upgrade from basic to advanced models for better oversight and uptime.

Below is a full breakdown of each type, their key features, and how to choose the right one for your data center.

Key Takeaways

• Basic PDUs provide passive power distribution with no monitoring or control, ideal for small, low-density setups.
• Metered PDUs feature local real-time power metrics to help balance loads, reduce waste, and prevent overloads.
• Switched PDUs deliver remote individual outlet control, enabling remote server reboots and scheduled power cycling to cut downtime.
• Choose based on your budget, monitoring needs, and remote management requirements.
• Intelligent PDUs (metered + switched) are the fastest-growing segment in modern data centers.

Basic Rack PDUs

Basic PDUs are the simplest, most passive type of power distribution unit. They function like heavy-duty extension cords for IT equipment, routing power from a single source to multiple rack-mounted devices with no built-in monitoring or control capabilities.

Core Features

• Pure power distribution with no metering, display, or network connectivity
• Metal enclosure with multiple outlets, power cord, and optional overload protection
• No onboard electronics means fewer points of failure and minimal maintenance
• Low upfront cost and wide compatibility with standard rack layouts

YOSUN Basic PDUs offer customizable options including plug types (10A/16A, IEC C13/C19), shell colors, and cable lengths, with full safety certifications (CE, UL, RoHS) and 100% pre-shipping testing.

Best Use Cases

Basic PDUs work best in environments where staff have physical access to equipment:

• Small server rooms, network closets, and office IT setups
• Temporary test labs and event deployments
• Low-budget, low-density racks with no remote management needs

They are not suitable for large, high-availability data centers, as they cannot provide load visibility or prevent overloads remotely.

Metered PDUs

Metered PDUs add built-in local metering to track real-time power usage at the rack level. They display current, voltage, and power metrics locally, giving operators visibility into load levels without extra software.

Core Monitoring Capabilities

Standard metered PDUs only show metrics locally. Upgraded monitored PDUs add network-connected remote viewing and outlet-level granularity.

Best Use Cases

Metered PDUs are ideal for organizations that need load visibility but not remote control:

• Colocation facilities billing tenants by actual energy use
• Enterprise server rooms working to improve energy efficiency and prevent circuit overloads
• Organizations transitioning toward intelligent power management

Studies show facilities using metered PDUs can reduce power waste by up to 20% through better load balancing.

Switched PDUs

Switched PDUs add individual remote outlet control, allowing administrators to power cycle devices from a web browser without physical access to the rack. This is the most capable and flexible of the three core types.

Core Features

• Independent on/off control for each outlet
• Remote server reboots and scheduled power cycling
• Optional Auto-Probe functionality: automatically power-cycles unresponsive devices when they stop responding to network pings
• Threshold-based alerts and proactive load management

YOSUN Switched PDUs (part of its Smart product line) support single-phase and three-phase configurations for standard and high-density enterprise racks.

Best Use Cases

Switched PDUs are the standard for high-availability and distributed data centers:

• Colocation facilities and remote edge sites where on-site visits are costly and slow
• Environments targeting maximum uptime and fast fault recovery
• Facilities with energy management goals requiring remote idle equipment power-down

They eliminate costly truck rolls for simple reboots, cutting downtime and operational expenses.

Full Comparison: Basic vs. Metered vs. Switched PDUs

Market data from 2025 shows basic PDUs held the largest revenue share by volume, while switched PDUs captured 22% of the market. Intelligent PDUs (metered and switched combined) are projected to be the fastest-growing segment from 2026 to 2033.

How to Choose the Right PDU

Selecting the best PDU depends on three core factors:

1. Budget: Basic PDUs are the lowest-cost option for simple setups.
2. Monitoring needs: Metered PDUs deliver the load visibility required for energy efficiency and overload prevention.
3. Remote control requirements: Switched PDUs are necessary for remote sites and high-availability environments.

YOSUN supports customers through a five-step process: demand analysis, design, production, testing, and after-sales support. With 30,000 units produced monthly across six assembly lines and 100% pre-shipping testing, they offer customized configurations for any data center environment.

FAQ

What is the main difference between basic and metered PDUs?

Basic PDUs only distribute power with no monitoring features. Metered PDUs add a local display showing real-time current, voltage, and power usage, so operators can balance loads and prevent overloads.

Can switched PDUs reboot a server remotely?

Yes. Switched PDUs offer individual outlet control, so administrators can power cycle a single server from a web browser. This eliminates the need for on-site visits for simple reboots and reduces downtime.

Do metered PDUs support remote monitoring?

Standard metered PDUs only show metrics locally via a built-in display. For remote viewing, you need a monitored or smart PDU variant, which adds network connectivity for remote access to power data.

Which PDU type is best for a small server room?

Basic PDUs are the best fit for small server rooms with few racks, where staff have easy physical access to equipment. They are low-cost, require no network setup, and deliver reliable power.

How does a three-phase PDU differ from single-phase?

Three-phase PDUs carry higher power loads, making them ideal for high-density server racks. Single-phase units work for standard lower-density racks. Both are available in basic, metered, and switched configurations.

Conclusion

The three types of rack PDUs — basic, metered, and switched — each solve distinct power management needs. Basic models deliver low-cost, reliable power distribution for simple setups. Metered units add load visibility for energy efficiency and overload prevention. Switched PDUs provide remote control to maximize uptime in high-availability and distributed environments. Match your choice to your budget, monitoring needs, and remote management requirements.