Exploring the power consumption of LAN switches in Depth

As the name suggests, LAN switches are mainly used in LAN and need to be online all the time, but their high power increases the enterprise's spending. Most network equipment vendors promise the power efficiency of LAN switches, but few can prove how much electricity their devices can save. The user not only needs to determine the operational efficiency of each supplier's equipment, but also needs to find an objective method to measure a product so as to make purchase decisions.

This is especially important because LAN switches need to be online all the time, while switches with high energy efficiency can save a lot of operation expenses, and some enterprises can save millions of yuan a year. To maximize profits, enterprises must test their energy efficiency. At present, many people boast about the power consumption test of LAN switches, but for the same device, the results produced by different people during the test are quite different. Next we will first explain the measurement indicators and other considerations of the power consumption and efficiency of LAN switches. The following describes how to measure the power consumption of LAN switches.

What factors need to be considered when testing the power consumption of LAN switches?

There are many factors that can affect the way LAN switches consume power. The network interface is either copper or optical fiber media, which directly affects the power consumption, as well as the number of active ports and the number of modules that need to transmit software on some layers of the network.

In addition, the deeper the communication check, the more power consumption. A layer-4 or above switch needs to be tested, which makes decisions based on the height of the data in the protocol stack and the depth of the data packets. This leads to a different data encoding path, which affects power consumption.

LAN Switch Power Consumption Test Indicators

1. Steady-State Power Consumption

Steady-state power consumption is often used in performance tests. However, from the perspective of power consumption, this is inaccurate. For example, a running fan will undoubtedly increase power consumption. Some manufacturers may allow the fan to run when the system is started, thus "testing" the fan (even if no heat dissipation is required ). Users can test power consumption five minutes after the device is powered on, which temporarily increases power consumption.

In addition, we also need to determine whether the steady-state power consumption is based on a device with an idle port or a device that is processing data communication. Regardless of the definition, it is important to note that cost calculation based on steady-state power consumption alone cannot be very accurate, because over time, switch traffic will not remain in the status of a single communication load.

2. modules/interfaces

To obtain accurate energy consumption figures, the LAN switch test must note all modules in use in the system. Even a switch with stackable or fixed ports may only use certain modules, which may potentially affect power consumption. In general, this option includes the uplink port and the stacked port used to connect a vswitch baseboard to another vswitch baseboard.

3. Influence of Power Supply

For a system that provides multiple power supplies, when the load is between 50% and 90%, the power supply is generally the most effective, so the power supply option is very important. For a modular system with low load, selecting the highest power function will lead to inefficient use of power supply and higher power consumption.