Be careful! Considerations for server power selection

The server power supply is frequently used by many friends at work. When the server power supply fails, it is very important to choose a new server power supply, because the server power supply is the "motive force" behind the stable operation of the server ". In the past, we introduced and paid much attention to energy-saving technologies on processors. Here we will mainly introduce the server power supply standards and what users should pay attention to when purchasing servers.

Two main power supply standards for server Power Supply

Server power supply can be divided into ATX power supply and SSI Power Supply according to the standard. The ATX standard is widely used for desktops, workstations, and low-end servers. The SSI standard is developed with the development of server technology and is suitable for servers of various grades.

The ATX standard is a specification launched by Intel in. The output power is generally ~ Between. The ATX Power Supply usually uses a 20Pin (20-pin) double-row rectangular socket to power the motherboard. With Intel's Pentium4 processor, the power specification is changed from ATX to ATX12V. Compared with ATX power supply, ATX12V power supply mainly adds a 4 Pin 12 V power output end, in order to better meet P4 power supply requirements, the power consumption of P4 at 2 GHz clock speed reaches 52.4 W ).

SSIServerSystemInfrastructure (SSIServerSystemInfrastructure) specification is a new type of server power specification jointly developed by Intel and a number of major IA architecture server manufacturers. The SSI specification was introduced to standardize server power technology, reduce development costs, and prolong the service life of servers, it mainly includes server power specifications, backplane system specifications, server chassis system specifications, and heat dissipation system specifications.

Four SSI specifications

According to different environments and scales, SSI specifications can be classified into four sub-Specifications: EPS, TPS, MPS, and DPS.

EPS specification EntryPowerSupplySpecification): it is mainly designed for low-end servers with single power supply. The Design adheres to the basic specification of ATX power supply, but there are some differences in electrical performance indicators. It applies to rated power between and ~ W power supply, used independently, not used in redundancy mode. Later, this specification was developed to EPS12VVersion2.0), and the applicable rated power reached ~ 650 W, the most intuitive difference between it and ATX12V power supply is that it provides 24 pin motherboard Power interface and 8 pin CPU power interface.

TPS specification ThinPowerSupplySpecification): Applicable to 180W ~ 275W system, with PFC (Power Factor Correction), automatic load current distribution function. The power supply system can achieve parallel redundancy of up to four Power Supply Groups, and the system provides fan cooling. TPS power supply has high requirements on hot swapping and balanced current distribution. It can be used for N 1 Redundancy and provides redundancy protection.

MPS specification MidrangePowerSupplySpecification): This type of power supply is defined as a high-end server system for more than 4 CPUs. MPS power supply is suitable for power at ~ Power supply, which can be used independently or redundant. It provides PFC, automatic load current distribution, and other functions. The power supply element voltage, current specification design and semiconductor, capacitor, inductance and other components operating temperature design margin exceeds 15.

DPS specification DistributedPowerSupplySpecification): the power supply is a single 48 v dc voltage output power supply system. The minimum power supply is 800 W, and the output is 48 V and 12VSB. DPS power supply using secondary power supply, input AC after AC-DC conversion circuit output 48 v dc, 48VDC and then through the DC-DC conversion circuit output load needs 5 V, 12 V, 3.3V DC. The establishment of this specification mainly aims to simplify the Power Supply Mode for telecom users, facilitate the power supply of data centers, and connect the power supply of the IA server with the power supply system adopted by China Telecom.

Bright Future of SSI standards

Although the current server power supply has two standards, ATX and SSI, but with the more standardized SSI standards, SSI specifications are more suitable for the development of servers, server power will also adopt SSI specifications in the future. The SSI specification is conducive to the development of the IA server. In the future, the CPU clock speed that can be supported will become higher and higher, the power consumption will increase, the hard disk capacity and speed will also increase, and the number of high-speed devices with plug-ins will increase.

In order to reduce heating and energy saving, the SSI server power supply will develop towards low voltage, high power, high density, high efficiency and distributed power supply in the future. The server uses a considerable number of accessories, supports four or more CPUs, and supports four or more mounted hard disks ~ 10. These accessories are large energy-consuming users. For example, high-end industrial standard servers use Xeon processors, and their power consumption has reached more than 80 W, while each SCSI hard disk consumes more than 10 W, therefore, the power required by the server system is much higher than that of the PC. Generally, a w power supply is enough for the PC, and a W power supply is required for the server until the power supply reaches kW. In actual selection, different applications have different requirements on server power. industries such as China Telecom, securities, and finance emphasize data security and system stability, therefore, high reliability is required for server power supply, which is also a development trend.

Considerations for purchasing server Power Supply
　
When purchasing a server, it is very important to check its battery quality. The quality of the power supply, including the output power, efficiency, ripple noise, timing, protection circuit and other indicators are up to standard or meet the needs. Pay attention to the credibility, scale, and support of Power Supply manufacturers. manufacturers with good reputation, large scale, and timely support, such as Delta, quanhan, and xinju, generally have relatively reliable quality, it will be much better in terms of cost effectiveness. For more information, see the following indicators:

Power options: W and W are common on the market. For individual users, W is enough, while for servers, because upgrading and increasing disk arrays require larger power support, it is appropriate to use a W power supply.

Security Certification: the current power supply must pass 3C Certification, that is, China's national mandatory product certification, ChinaCompulsoryCertification). Only strict consideration of product quality, consumer safety, health, and other factors, strict inspection of products according to different standards can pass international certification. Safety Certification is an important indicator for us to choose power supply, which should be the most important point when we choose power supply.

Voltage retention time: for this parameter, the UPS problem is mainly considered. The general power supply can meet the needs, but if the UPS quality is not reliable, it is best to choose a power supply with a long voltage retention time.

Redundant power supply Selection: This is mainly for servers with high system stability requirements. Redundancy generally includes Dual Redundancy and triple redundancy.

Support for the motherboard: This factor does not seem important, and is rare in the home PC, but it exists in the server, so pay attention to the purchase.

Technical specifications for server power saving

1. Multi-country certification mark: High-quality power supply has certification marks such as FCC, us UR, and China Great Wall, certification has strict standards in terms of production processes, electromagnetic interference, and security protection, and has a certain authority.

2. Noise and filtering: Of course, the lower the noise, the better. The filter index is the stability of the DC voltage. The filtering quality is directly related to the AC component in the output DC, also known as the ripple coefficient, the smaller the coefficient, the more favorable it is for the safety and stability of each part.

3. Voltage holding time: Generally, high-quality power supply can be maintained for 12-18 ms to ensure normal power supply during UPS switching.

4. Electromagnetic Interference: there are international fcc a and fcc B standards, and there are also national A (industrial level) and National B (Household Electrical level) standards in China, high quality power supplies can all pass level B standards.

5. Power Supply life: Generally, the power supply life is calculated according to the possible failure cycle of the component in 3-5 years, and the average working time is between-hours.

In addition, there are various technical indicators such as power efficiency, overvoltage protection, boot delay, and instant response capabilities to fully ensure the reliability of server power supply!

A standard green and energy-saving server must meet the following requirements:

1. The conversion efficiency under typical loads reaches 80%.

The so-called typical load refers to the power load reaches 50% of the rated power, for example, the rated power supply of 400 W, its typical load is 50% * 200 = W. The conversion efficiency of the energy-saving power supply must reach 50% under 80% load.

2. the standby power is less than 1 W

The standby power refers to the load power of the server when it is shut down. After the power supply is turned off, as long as the circuit of the power supply plug-in board is continuously turned on, the power supply will provide the motherboard With a standby voltage of + 5 VSB. The server boot, network wake-up, and keyboard boot are all related to + 5 VSB. Generally, the + 5 VSB has a weak current, and the power consumption may occur if there is a current. When the current on the voltage of the + 5VSB is 0.1A, the input power of the power supply should not exceed 1 W. That is to say, the conversion efficiency of the power supply should be higher than 50%.

3. the power factor reaches 0.8.

Power Factor is an easy indicator to ignore. The power factor is related to the energy saving of the State Grid System. The power factor of the server's energy-saving power supply must be above 0.8. Power supply using active PFC circuit, the power factor can reach more than 0.9, and some even up to 0.99.

After understanding the above indicators, I believe you will be aware of them when purchasing server power.

1. Server power specifications
2. Server power: 80% the culprit of server Paralysis
3. How to buy the right power supply for the server