As the name implies, server power refers to the power supply (POWER) used on the server. Like the PC (personal computer) power supply, it is a switching power supply.
According to the standard, server power can be divided into two types: ATX power supply and SSI power supply. The ATX standard is more commonly used and is mainly used in desktops, workstations, and low-end servers. The SSI standard is developed with the development of server technology and is applicable to various grades of servers.
ATX standard
The ATX standard is a specification that Intel introduced in 1997. The output power is generally between 125 watts and 350 watts. ATX power supplies typically use a 20Pin (20-pin), double-row rectangular socket to power the motherboard. With Intel's Pentium 4 processor, the power supply specification was also modified by ATX to ATX12V. Compared with ATX power supply, ATX12V power supply mainly adds a 4Pin 12V power output to better meet the Pentium 4's power supply requirements (2GHz frequency P4 power consumption reaches 52.4 watts).
SSI standard
The SSI (Server System Infrastructure) specification is a new server power specification introduced by Intel together with some major IA-architecture server manufacturers. The introduction of the SSI specification is to regulate server power technology, reduce development costs, and extend the service life of servers. Includes server power specifications, backplane system specifications, server chassis system specifications, and cooling system specifications.
According to the different environments and scales used, the SSI specifications can be divided into four seed specifications: TPS, EPS, MPS, and DPS.
The EPS (Entry Power Supply Specification) is mainly designed for single-supply low-end servers. The design adheres to the basic specifications of the ATX power supply, but there are some differences in the electrical performance specifications. It is suitable for power supplies with rated power from 300 watts to 400 watts, used independently, and not used in redundant mode. Later, the specification was developed to EPS12V (Version2.0), and the applicable rated power reached 450 W to 650 W. The most intuitive difference between it and the ATX12V power supply is that it provides a 24Pin motherboard power connector and an 8Pin CPU power connector. Lenovo Wanquan 2200C/2400C uses EPS standard power supply, output power is 300W, the power input voltage is wide range of 90 ~ 264V, power factor is greater than 0.95, due to the use of high-standard components, its average time between failure ( MTBF) is greater than 150,000 hours.
TPS (Thin Power Supply Specification): Applies to 180W to 275W systems, with PFC (Power Factor Correction), automatic load current distribution. The power system can implement up to 4 sets of power supplies in parallel and operate redundantly. The system provides fan heat dissipation. The TPS power supply has high requirements for hot swap and current equalization. It can be used for N+1 redundancy and has redundant protection.
Midrange Power Supply Specification: This power source is defined as a high-end server system that targets more than four CPUs. The MPS power supply is suitable for power supplies with a rated power of 375 W to 450 W and can be used individually or redundantly. It has PFC, automatic load current distribution and other functions. The design margin of the working temperature of the devices such as voltage, current specification and semiconductors, capacitors, and inductors exceeds 15%. In the ambient temperature of 25 degrees or more, the maximum load, redundant working mode, the MTBF can be up to 150,000 hours.
DPS (Distributed Power Supply Specification): The power supply is a single 48V DC voltage output power supply system, providing the minimum power of 800 watts, the output is +48V and +12VSB. DPS power supply using secondary power supply, input AC through the AC-DC conversion circuit After the output 48V DC, 48VDC and then through the DC-DC converter circuit output load required +5 V, +12 V, +3.3 V DC. The development of this specification is mainly for the purpose of simplifying the power supply mode for telecommunication users, facilitating power supply in the engine room, and bringing the IA server power supply into line with the power supply system used by telecommunications.
Although there are currently two standards for ATX and SSI in server power supply, as the SSI standard is more standardized, the SSI specification is more suitable for the development of servers. The server power supply will also adopt the SSI specification. The SSI specification is conducive to promoting the development of IA servers. In the future, the CPU frequency that can be supported will become higher and higher, the power consumption will increase, the hard disk capacity and speed will increase, and more and more high-speed devices will be available. . In order to reduce heat generation and energy saving, SSI server power will develop in the direction of low voltage, high power, high density, high efficiency, and distributed power in the future. The server uses a lot of accessories. The supported CPU can reach 4 ways or more. The mounted hard disk can reach 4 to 10 blocks, and the memory capacity can also be extended to 10GB. These accessories are large consumers of energy. For example, high-end industrial standard servers use Xeon processors and their power consumption has reached more than 80 watts (W), and each SCSI hard disk consumes more than 10 watts (W), so the server system The power required is much higher than that of a PC. A typical PC requires only 200 watts of power and the server requires more than 300 watts of power up to a kilowatt. In actual selection, different applications have different requirements for the server power supply. Industries such as telecommunications, securities, and finance emphasize data security and system stability. Therefore, server power supplies must have high reliability. At present, high-end servers use redundant power supply technology. They have functions such as current sharing and failover, which can effectively avoid the impact of power failure on the system and achieve 24×7 non-stop operation. Redundant power supplies are more common than N+1 redundancy, which guarantees that the system will not fail in the event of a power failure (there is a very low probability of more than two power failures occurring simultaneously). Redundant power supplies usually work in conjunction with hot-swap technology, ie, hot-swappable redundant power supplies. They can unplug the failed power supply and replace it with a good one when the system is running, which greatly improves the stability and reliability of the server system. Sex.
When buying a server, pay attention to the power of the unit. At a minimum, you should pay attention to the following two points:
1. The quality of the power supply, including the output power, efficiency, ripple noise, timing, protection circuit, and other indicators meet or meet the needs;
2. Pay attention to the credibility, scale, and support of power supply manufacturers. Manufacturers with relatively good reputation, large scale, and timely support, such as Delta, Quanhan, and New Giant, etc., generally have relatively reliable quality and good cost performance. a lot of. When purchasing, please refer to the following indicators:
The choice of power: 300W and 400W are common in the market, 300W is enough for individual users, but for servers, because of the upgrade and the ever-increasing disk array, it needs more power. To support it, it is appropriate to use a 400W power supply for this purpose.
Safety certification: only strictly consider the product quality, consumer safety, health and other factors, the product is strictly tested according to different standards in order to pass the internationally qualified certification, safety certification is an important indicator of our purchase of power, This should be the most important point when we choose the power supply. Because it is related to our safety and health. Poor power supply noise is significant and has an impact on the human body. Saving a few hundred dollars in this area is not worth the candle. Current power supplies are required to pass 3C certification. (3C certification is short for "China Compulsory Cerlification". Actually, CCEE (China Electronic and Electrical Products Safety Certification), CCIB (China Imported Electronic Product Safety Certification), EMC (Electromagnetic Compatibility) ) Three certificates are merged, and 3C certification will be enforced after May 1, 2003.)
Voltage holding time: For this parameter, the UPS problem is mainly considered. The general power supply can meet the requirements, but if the UPS quality is not reliable, it is better to choose a power supply with a long voltage holding time.
Redundant power selection: This is mainly for servers with high system stability requirements. Redundancy generally has double redundancy and triple redundancy.
Support for the motherboard: This factor does not seem important, and is rarely seen in home PCs, but it is a phenomenon in the server, so pay attention to when purchasing.