In the data center market, the electricity bill is a huge expense which has eroded the profits of enterprises.For example, in the year of 2012,China Unicom earned 40.7 billion dollars in revenue and made 1.2 billion dollars in profits , but its electricity bill was as high as 1.7 billion dollars — — what a huge bill…
Costs and profits are the eternal theme of entrepreneurs, we used to know too little about the energy consumption of data centers, and now this issue should be taken seriously by more people.
How about the present, future & answers?
In the year of 2017, about eight million data centers around the world, from small server cabinets to large data centers, are processing data loads.These data centers consume 416.2 Twh of electricity, equivalent to 2% kwh of the world’s total electricity consumption.It is estimated that there will be 300 trillion or more connected devices worldwide by 2020.The 44ZB data to be generated and used by the IoT will be processed by 400 million servers in 4,000 data centers.The data center will use up to 5% or more of the world’s electricity.
It is clear that most of the load and data in modern life have quickly depended entirely on the data center.But as data flow increasing and data centers are being built, people create a better world through data,there will be growing resource and power demand for data centers.In addition to the industry leaders of super-massive or high-performance data centers such as Microsoft, Facebook, Amazon and Baidu, energy efficiency has not been concerned as priority comparing with other issues from the data center operator.However, if people do not rethink about the energy efficiency and indicators of the data center, they will have to pay heavier bills in the near future.
Propose a measure
In the past, people did not have a clear understanding of power consumption and cost, and adopted a relatively extensive economic development.After learning a lot of lessons, the data center builders began to realize the disadvantages of unreasonable energy consumption and took corresponding measures to change it.
Christian Belady came up with the famous concept of PUE,it is used as a measure of the efficiency of the data center and the reduction of green energy efficiency.What is PUE?Start from the definition, PUE = the total liability rate/it requirements rate.The base value of PUE is 2, which means that the 1w power consumption of chip-level master device will cause the total power consumption of 2w.Currently, the PUE value of advanced data centers is usually below 2, while the average PUE value of data centers in China is between 2.2 and 3.0.
With PUE values, we can have a clear understanding of the power consumption of the data center.For example, the construction of a data center of 3,000 racks, with a final load of 3kw * 3000 = 9000kw per power of 3kw,the annual power consumption is 9000kw * 24 h * 365 days = 78840000kwh.The annual electricity bill of 78.84 million yuan, plus air conditioning, new wind, lighting and other power consumption in the data center, calculated at 1 yuan/kwh.The annual electricity bill is worth 800 million yuan.So,if measures are taken to reduce the PUE value, there will be no small reduction in financial expenditure.
Analysis of sources of power loss
Harvey Thompson has a famous book, “who stole my clients?” Which vividly describes the reasons for the loss of clients and is selected to the Harvard business school’s boutique book list.Data center builders may also be able to produce a corresponding book, “who stole my power?” Let’s see, what are the factors?How are we going to solve it now?
1. Chips
There is no doubt that the chip is the key factor of the data center product, especially on the high-speed chip.In the research of 400G optical transceiver ,people often hesitate on the technological path — — DSP or CDR?The criticism of the DSP is coming when the power consumption is taken into consideration.
How about the server chips?Take Intel as an example,in the early years, the consumption of their CPU was about 120 watts, and now the latest Cooper lake has reached 240 watts.For GPU, the latest HGX2 GPU in NVIDIA has reached 400 watts.It goes without saying that with the improvement of computing power, the consumption of chips will increase in the future.Today, Moore’s law has failed, and the industry needs to find a feasible technological path to reach 400G optical network transmission in the future.
2、Servers and interconnection products
The high performance and low consumption servers have been the new products developed by the industry, especially the Inspur and Huawei in China, which have rich experience and advantages.Storage area network and interconnection between servers are mainly combinations of AOC, DAC and optical modules with fiber jumping lines.High rate (400G)and low delay (ns) represent the future trend of data center,which require for the high performance of interconnecting products ,while staying on a low level consumption and cost.
Optical transceiver has many types of loss factor, such as insert loss,crosstalk and so on. The reasons sometimes seem complex.With the development of technology, the current mainstream QSFP28 encapsulated modules can generally be controlled below 2.5w.Chinese enterprises also have excellent products, such as Gigalight.In the past few months,Gigalight made 100G QSFP28 PSM4 transceivers by Silicon chips technology,which proved that the reduction of consumption requires the application of new materials.
3. Cooling system
High power density racks bring great cooling challenges. The national laboratory of Lawrence Berkeley in the United States analyzed the energy distribution of the data center of PUE1.9.It was found that 47% of them came from electricity and cooling consumption.At present, the data center uses wind and cold mode, and in most cases, it provides 8kw of refrigeration power per unit.According to statistics published by the ASHRAE organization,The maximum power density of a single rack will reach 40 kw per rack by 2020.The cold wind has consumed a lot of electricity and its performance is worrying in the future.However,new way is emerging.The immersion liquid cooling technology used in Alibaba’s plan brings the PUE value close to the theoretical limit of 1.0.
Even so, the immersion cooling technique is not mature enough.In terms of basic components, attention should be paid to material compatibility and signal compatibility.It needs to be verified in the liquid environment, CPU,storage, hard drives, and so on, whether they can work steadily and reliably for a long time, and whether performance will be affected.In addition, this new technology may need to reconstruct the data center, re-server to achieve the best results.The implementation of these projects should be put on the question mark.
4、Others
There are other reasons for the consumption of electricity, such as lighting, system architecture, normal dimensions, reliability, and so on.Of course they are inevitable.In addition, natural cooling technology is highly dependent on meteorological conditions, and in a vast country like China, from the subtropical monsoon climate in Guangdong to the temperate continental climate in Xinjiang,different climates bring different construction environment.
For example, some data centers must be built in the humid and hot south China area, such climatic conditions are not conducive to heat dissipation,it will be another challenge that how to get low PUE values and optimized TCO in such areas which the data center must face.
Conclusion
The above is the analysis of power loss and some of the current schemes, although they are not yet completely systematic and scientific, but people have begun to act.On the construction of the data center project, more questions must be asked:
1. For the head of the data center, how big is the energy bill of the data center?
2. For the chief financial officer: how much will it cost to build a data center?How much real income can enterprises get through the equipment of the data center?How to reduce the budget as much as possible?
3. For the chief technical officer, how to use a scientific and effective cooling method?How to make a structural transformation?How to choose servers, optical transceivers, fibers and other products?
4. For the chief executive, how can a company achieve greater sustainability in the future?
If the above questions can be answered well, the future construction of the data center will be full of hope.The energy efficiency of the data center must be taken seriously by all enterprises and operators.It is the responsibility of all high and new technology entrepreneurs to establish green, sustainable and efficient data centers and to continue to improve existing technological disadvantages.The ultimate goal of harmony between man and nature is the vision of all.
