What Makes a Modern Data Center Tick? From History to Architecture

What Is an IDC?

An IDC, or Internet Data Center, is a massive facility that houses thousands of servers for centralized data storage, computation, and exchange, and it is essential for handling virtually all internet traffic.

Data Center Development Stages

In the 1960s, large‑scale computer rooms called "server farms" emerged as the earliest prototypes of data centers. The 1990s saw the rise of internet‑driven services, leading companies to host servers either internally or in carrier‑managed facilities. In 1996, Exodus coined the term "IDC". The late 1990s introduced virtual machines (e.g., Virtual PC, VMWare) and virtual hosting, enabling multiple websites on a single server. The early 2000s brought cloud computing, transforming physical server rental into virtualized, containerized resources and giving rise to IaaS, PaaS, and SaaS models.

Data Center Architecture

Modern data centers consist of two main categories of hardware: primary equipment and supporting equipment. Primary equipment includes servers, storage arrays, and networking devices such as switches, routers, and firewalls. Supporting equipment provides power, cooling, fire protection, monitoring, and building management.

Servers are high‑performance computers composed of CPU, memory, motherboard, storage, GPU, and power supplies. While Intel architectures dominated historically, domestic ARM‑based CPUs are gaining market share for better cost‑performance. Servers are mounted in racks (typically 42U, 600‑800 mm wide, with varying depths).

Storage devices include HDDs and SSDs; HDDs remain cost‑effective for bulk storage, while SSDs serve high‑performance workloads.

Networking devices include switches, routers, and firewalls. Top‑of‑Rack (TOR) switches sit at the rack level, connecting servers to higher‑level switches. The prevalent data‑center network topology is the spine‑leaf architecture.

High‑bandwidth data transmission relies on fiber optics, optical modules, and optical transport networks (OTN). High‑speed optical modules (e.g., 400 G) are a significant cost factor.

Data Center Interconnect (DCI) links multiple data centers, driven by the "East‑Data‑West‑Compute" strategy and increasing inter‑data‑center traffic.

Power systems include medium‑voltage and low‑voltage distribution cabinets, UPS units, and increasingly, HVDC (High Voltage Direct Current) combined with grid power for higher reliability and efficiency. Both 220 V AC and -48 V DC are used, with DC gaining traction for lower losses.

Cooling systems are the second largest energy consumer after IT equipment. Two main methods are used: air‑cooling (traditional HVAC) and liquid‑cooling, which offers up to 30‑50% energy savings and significantly lower noise.

Modern data centers adopt close‑coupled cooling at rack or cabinet level to improve efficiency.

Additional infrastructure includes environmental monitoring (DCIM), fire suppression using inert gases, and modular construction that reduces build time from 18‑24 months to about six months.

Conclusion

Data centers are critical infrastructure for the digital economy, driving national competitiveness. Under the "East‑Data‑West‑Compute" strategy, China’s data‑center market is projected to reach ¥3,200.5 billion in 2022 and ¥7,070.9 billion in 2025, with a focus on greener, AI‑enhanced, and more intelligent operations.