Over the past year, global investment in data centers has increased by more than 20%. This is largely driven by increasing demands related to cloud services, ‘Big Data’, social media applications and innovations such as data center infrastructure management (DCIM). It won’t come as a surprise that data center energy requirements have also grown massively. Despite industry-wide initiatives, high energy prices and legislation, power demand is on the increase. Network Convergence, however, may play an important role in making power consumption at data centers significantly more efficient.
According to the DatacenterDynamics 2012 Global Census, global data center power requirements grew 63% to 38GW in 2012, up from 24GW in 2011. The study also noted an kW increase per average data center server rack. Although the proportion of more energy efficient HD racks (> 10 kW per rack) grew by 3%, the percentage of less efficient medium-density racks (5-10kW per rack) grew by the same amount equal.
Data Center efficiency is typically measured in Power Usage Effectiveness, or ‘PUE’. A PUE of 1 means that all energy going into the Data Center is used exclusively for IT. A PUE of 2 means that for every watt of power used for computing, another watt is consumed for power distribution, cooling and related processes such as lighting, heating and security systems. The 2012 Data Center Survey, published by the Uptime Institute, places today’s global average PUE somewhere between 1.8 and 1.89. Understandably, regulators and other stakeholders are calling for data centers to use energy in the most efficient, environmentally sound way possible. Building data centers in cold areas to save on cooling is just one example.
Data Center efficiency with less energy
Another way of cutting power consumption is through deployment of converged networks in the data center. What we mean by ‘network convergence’? Years ago, in-building resources were be grouped and devoted to one particular function: telephony, internet, security, building infrastructure, data and so on... Today, however, we’re seeing integrated pools of computers, storage and networking resources increasingly being shared across multiple applications. This is enabled by automatically allocating resources to specific processes, on the basis of precisely pre-defined policies.
'Converged infrastructure' provides enormous technical and business efficiency increases. It helps reduce overall power consumption in the data center, improves cooling efficiency and enables the introduction of further energy-saving measures, which we will look into in more detail below. Network convergence essentially relies on the creation virtualized server, storage and networking capacity, which is shared across multiple applications. This allows companies to reduce the footprint of all elements in the data center. Virtualization requires less hardware to achieve the same levels of performance and manage the same workload and supports the latest generation of energy-efficient data center equipment.
Extra benefits of convergence in the data center
Besides energy efficiency enhancements, convergence can also makes it easier to implement critical functions and can improve the responsiveness of the IT department. Enterprises planning to invest in converged infrastructure offerings can look forward to cutting down the sprawl of cables in the facility and the number of obstacles in the raised floor's air path. Users don’t need to store as many cables in raised floors. This doesn’t only save on materials and resources but also improves air circulation. That saves energy. In addition, servers and switches need less transmission and signal processing power when links are short and signal transmission is undisturbed. They don’t heat up as much, so less cooling power - and therefore energy - is required.
The introduction of next-generation technologies also allows the use of thinner cabling, which means you can take the cabling out of the raised floor and place it up above, so the ventilation in the computer room functions with greater efficiency and less energy. Valuable space can also be saved with this type of cable management. The computer room can be smaller. That too ultimately improves energy consumption. The latest generation of cabling also has an improved noise ratio, and therefore requires less power for noise canceling.
Convergence supports monitoring
Monitoring network ports, cables, connectors and components in real time with an intelligent infrastructure management system will also pay off. If you have a full overview and total control of the physical infrastructure, you’ll automatically use it more efficiently. You only keep operating the capacities you really need. This means energy and material consumption can be further optimized. A survey by Frost & Sullivan found that as many as 40 percent of the switch ports are ‘forgotten’ in the ongoing operation of a large data network. They remain unused because the operator does not have a full and current overview of the infrastructure. Intelligent, automatic infrastructure management can substantially improve efficiency and thereby lower operating costs.
EEE and PoE +
An big feature of convergence is the fact that it enables the introduction of Energy Efficient Ethernet, according to the IEEE 802.3az standard. When a link is idle, the power consumption of physical layer devices is reduced by placing part of the transmission circuit into low power mode, without impacting data transmission. An EEE-defined protocol enables Ethernet devices (in LPI mode) to keep operational parameters updated. This preserves link stability and avoids disconnections. When the link is required once again, it is simply ‘woken up’ after a predetermined delay.
Power losses caused by idle circuitry are a concern, with millions of new switches being added to the already substantial installed based each year. However, the use of Power over Ethernet, or PoE, is also facilitated with network convergence. This combines power and data transmission in a single cable, allowing for extensive use of powering devices using data cabling. The original PoE standard, introduced a decade ago supported up to 12.95 watts, but PoE +, introduced in 2009, supports up to 25.5 watts. PoE can now power devices over long lengths of data cable.
In the 'converged' environment, Ethernet is no longer just used for transporting data, but networks an ever-growing number of devices and allows users to make the most of system intelligence. Convergence in the data center centralizes management of IT resources, consolidates systems, boosts resource utilization rates and lowers costs. This has repercussions on data center design and a significant positive effect on power requirements and distribution efficiency.