As you all know, the chassis has never been the most important position for the PC, but in the server, the position of the chassis is very high, especially for 1U servers. It can be said that the quality of the chassis is to some extent. This has greatly affected the stability of 1U servers, but the current 1U server chassis market is still chaotic, making many consumers wonder how to choose. Here I will focus on this topic, based on the questions raised by the readers, do my best Knowing to do some answers, so this article is mainly written for friends who are assembling server enthusiasts at this level. It is not worth the noble veterans who fiddle with the dual Xeon motherboards of several thousand dollars all day. It's an old diyer's personal opinion, bias and impropriety are inevitable, and I hope everyone can correct me.

Classic question one: What are the most important indicators of the product when purchasing a 1U rack server chassis?

This is one of the questions asked by the most readers. The author thinks that the most important factor is heat dissipation. The quality of heat dissipation is the most important indicator for purchasing a 1U chassis. If the heat dissipation is not good, everything else will be wasted. This problem is not very obvious in the P3 era. Generally, 1U chassis Just add two or three fans and a P3 ultra-thin radiator to solve the problem, but now it has entered the P4 high temperature era! My feeling is that after the main frequency of P4 crosses into 2.8G, the temperature has risen. If you don’t seriously consider the heat dissipation structure of the chassis and scientifically design the air path, it will be difficult to avoid crashes and burnout components, especially for the new Prescott core. For P4, such as P4-3.0E and P4-2.4A, the temperature can rise to 90 degrees at will! With such a hot core running in such a small volume of 1U, where does the stability come from? Therefore, carelessness does not work.

So how can we distinguish the heat dissipation of the 1U chassis? For most compatible chassis, it is impossible to make a heat dissipation hood for a specific type of motherboard like a brand server chassis.

Because if there is a windshield in the case that is particularly suitable for a certain kind of motherboard, then the compatibility of this case is definitely not good, and it cannot be suitable for more motherboard applications. Although the layout of the motherboard cannot be said to be ever-changing, there are many types. DIY chassis must have particularly good compatibility in order to meet the heat dissipation requirements of most motherboards. This is why 1U rack-mounted servers such as Dell and HP can do well in heat dissipation. Because the heat dissipation structure inside their case is specifically designed for a certain type of motherboard they use, there is no need to consider whether this air duct design can be compatible with the heat dissipation of other types of motherboards. In fact, this approach is used in some imports. It’s also reflected in the expensive 1U chassis. Many imported cases and so-called high-end 1U cases are actually designed for certain dual-Xeon high-end motherboards. If you replace a PC motherboard, many components will be blocked in the wind. Very poor, so buying a 1U server chassis is not the more expensive the better, but it depends on the compatibility of the 1U chassis in the heat dissipation design, whether it can adapt to the heat dissipation requirements of various motherboards, especially PC motherboards, because many friends want to assemble It is a 1U value server based on PC motherboard.

The amount of fans is the guarantee of the wind path design

Since you don't look at the windshield, look at the wind path carefully, that is, look at the chassis cooling fan, mainly depending on the number, layout, air volume, and quality of the fans. First of all, the number of fans is very important. Everything changes from quantitative to qualitative. There can be no qualitative change without quantity. Therefore, the air volume of the chassis is directly related to the number of fans. This is undeniable. There is now an argument. There are too many fans, as long as the layout of the air path is good. In fact, this is a stale concept. It is still fair in the P3 era, but it is now outdated. Now we are facing a CPU with dozens of watts and hundreds of watts. , It’s not enough to have a good air path layout. Don’t think about using any clever air path design to use one or two fans to solve the problem, and if there is a slight problem with the fan, your clever design may become a disaster . Therefore, we must first ensure that there are enough fans in order to discuss the layout. For example, a 1,000 square meter waiting hall needs to install 30 fans to meet the cooling needs of passengers, but only 5 fans are installed. The result is imaginable. But knowing that without the guarantee of quantity, no matter how reasonable the layout of the wind path is, the desired effect will not be achieved.

Adding fans will burden the power supply?

There is also a saying that adding cooling fans will increase the burden on the power supply. In fact, it is wrong to say that if there are more fans, the air flow inside the chassis must increase accordingly. This is an objective fact. As for the increase in the power supply burden, you don’t need to worry too much. , As long as it is a high-quality server power supply with sufficient power and a few fans with a few watts, there should be absolutely no problem, and the internal temperature of the chassis is reduced, which is also very good for the life of the power supply. The power supply is also a big heat generator. At present, the mainstream 1U server chassis on the market has more than six internal cooling fans, which can generally support P4-2.X CPUs well. Faced with P4-3.X inevitably entering the mainstream market, domestic manufacturers and R&D Institutions are also taking active actions. For example, some domestic manufacturers have launched a ten-fan 1U server chassis with good heat dissipation effects. They use imported large motors with 40×28 copper core fans. The wind force is very amazing, which is not seen on ordinary PC cases. To that shocking feeling of wind.

There are also some unique designs designed specifically for PC motherboards, which not only support P4-3.0E but also support all AMDxp CPUs, which makes friends who like AMDxp2500+ really happy. Otherwise, it is really difficult to support a high-heating CPU. Now the power of a high-frequency P4 has reached about 100 watts. How high is the temperature of a 100 watt light bulb? The newspaper can be baked.

A turbo fan must be good?

I would like to mention here that some friends are very superstitious about turbofans. They think it’s good to have turbofans in the case. In fact, this is a misunderstanding. Due to design problems, the air volume of turbofans is slightly stronger than that of direct blowing fans. The wind of the fan is too concentrated, so the heat dissipation inside the entire server is uneven, which easily causes too many dead spots for heat dissipation. Now some JS on the market is refurbished with old foreign turbofans for use. The price is very cheap, but it is used in The server is really worrying. The authenticity can be seen from the price. Not to mention the imported ones, they are the domestic high-quality turbofans (large caliber). They are ordered according to 10,000 pieces, and the ex-factory price is not less than tens of yuan. However, some low-quality cases only cost more than 300 yuan with fans. If you use high-quality fans, four fans only cost more than 200 yuan. What quality is the case? How does js make money? Haha, you can see what's going on at a glance.

Secondly, it depends on the layout of the fan. A good and scientific fan layout can send heat away as soon as possible, and the cold air can be sent as soon as possible. This mainly depends on the following aspects:

First, there must be enough powerful fans near the motherboard to dissipate heat, mainly to blow the CPU, motherboard chipset, and preferably to the memory and motherboard power supply circuit to avoid the motherboard capacitors from bursting due to excessive temperature for a long time;

Second, it is best to have cold air enter the fan, that is, to add cold air from the outside of the chassis. It is particularly good for the heat dissipation of the chassis. It is the key to cooling the high-frequency CPU. This is not available in many high-end chassis, so the price High never means good performance;

Third, it is best to have a hard disk cooling fan. Nowadays, large-capacity high-speed hard disks are becoming more and more popular. You can try to touch the surface of the large-capacity IDE hard disk after the computer has been running for a period of time. You will find that the temperature is very high, even hot. , The server has been running for many years without shutting down. Continuously running at such a high temperature, the hard disk is prone to read and write errors and even component damage. Special reminder is that you must choose a structure that separates the cooling fan and the hard drive. Do not use the hard drive cooling fan that is directly screwed on the bottom of the hard drive on the market, because the vibration of the fan will be directly transmitted to the hard drive. The rotation speed is above 7000 rpm, and the slight vibration will have an adverse effect compared to the hard disk, and this kind of vibration is continuous, and the hard disk will be damaged after a long time. There are many examples of this now. Therefore, when we choose a 1U chassis, for the hard disk, it is best to choose a hard disk cooling fan assembled according to the principle of "zero vibration", which can not only heat the hard disk, but also enhance the heat dissipation of the motherboard and CPU.

Fourth, it is best to have a power supply auxiliary cooling fan. Now the main heat generators in 1U servers are the power supply, except for the CPU, hard disk, and motherboard. In a 1U space of only four centimeters in height, a power supply needs to burst out 300 watts. The heat output of the above power is amazing, and limited by space, the heat dissipation is often not very good. After a long time, the components of the power supply are prone to aging or even damage. Therefore, the inside of the chassis should provide a cooling fan for the power supply, preferably Blowing directly on the power supply, rather than drawing from the side or behind the power supply, the effect of direct blowing is indeed much better than the ventilation.

Classic question 2: What special requirements does 1U server have for power supply?

The power supply dedicated for 1U server is a specially designed ultra-thin power supply, which is generally purchased together with a 1U chassis. A high-quality power supply is a direct guarantee for the safe operation of the server. It must not be sloppy or cheap. Although the principle of 1U server power supply is not complicated, because it runs 365 days a year in a small 1U space with poor heat dissipation, the durability of the power supply components is very demanding. The quality of general PC power supply is not comparable to that of servers. The power supply is on the same level. It can be said that the lowest-end server power supply has higher requirements than the most high-end PC power supply. What's more, the 1U server power supply works under harsh conditions and its quality requirements are more than that of the tower server power supply.

The 1U server power supply that can be bought in China nowadays, one is imported, the other is domestic. The price of real imported power supply is generally very expensive. Imported 1U power supply with 200 watts of power is generally around 900 yuan. Many distributors claim that their power supply is a famous brand from Taiwan or abroad, and the price is only 5 to 600 yuan. This kind of thing is very doubtful. Once I saw a counter selling a Taiwan brand 1U power supply, the price is not low, I According to the company’s website, they called directly to ask them the authenticity of the power supply. As a result, they said that they had never commissioned anyone to sell the power supply in China. It was strange that I could see their power supply. I mentioned some characteristics of the power supply, and they immediately identified it as a counterfeit. . Profiteers know how to take advantage of mainland users’ superstitious beliefs about Taiwan’s power supply. It is easy to fake it, and just put a fake label on it. In fact, the principle and technology of server power supply are no longer a secret. As long as the quality of the components and the processing level are guaranteed, the domestic brand-name 1U server power supply is completely comparable to imported products. Some domestic power supplies have actually done a good job, personally. I believe that in addition to quality, the purchase of a 1U server power supply also requires after-sales service, that is, whether the manufacturer can truly guarantee replacement. There is no 100% failure-free power supply in the world. Even if you choose an international brand-name power supply, there is no guarantee that it will never fail. If that is the case, then there is no need to design expensive redundant power supplies, right? This requires the manufacturer's after-sales service to be in place. In this regard, I tend to choose domestic manufacturers with a long history and a high reputation.

Classic question 3: Is the thickness of the 1U server chassis the better? Is the pure aluminum chassis better than the pure steel chassis?

In fact, the reason why these problems are concerned by consumers is largely due to the concept hype of manufacturers. Some people even say how many millimeters their chassis steel plates have reached, so how good the quality of the chassis is. Think about it. So what do you do? No one stepped on it. Compared with home computers, servers sometimes don’t move once in a few years. They are placed firmly in a steel cabinet. Up to three stacks are separated by partitions. There is no heavy pressure and heavy protection. Even if you move, be careful and handle it. The thickness of the chassis steel plate is not a key issue. I see that some consumers twist or press the chassis hard to try the thickness of the sheet when buying a 1U chassis. In fact, this is quite funny. For a 1U chassis that lies flat, No matter how thick the steel plate is, it can only increase the weight at most, and it does not reduce the vibration like our usual PC case.

In addition, it should be emphasized that too thick plates will take up too much space. Think about the 1U height is 44.45 mm, which is calculated and planned according to one hundredth of a millimeter. The box body is one millimeter thick. , The internal space of the case is one millimeter less, and the direct result is reduced compatibility. I personally saw a friend bought an imported brand-name 1U pure copper radiator and installed it in a domestically made 1U case with a low quality of more than 300 yuan. The height was not enough. Can't put the lid on, regret it. The key to buying a case depends on the heat dissipation. In addition, is the so-called pure aluminum chassis better than pure steel chassis? I think this is even more an illusory concept hype. It doesn’t make much sense. Everyone knows that when you look at the world-famous servers, there are very few pure aluminum chassis. The application of pure aluminum chassis on the server is basically equivalent to the application used in the PC. For embellishment, some people say that the pure aluminum chassis has good heat dissipation. In fact, everyone understands that this is mostly a psychological effect. The material of the cabinet plate can never be the key to the server's heat dissipation. There is really no need to spend more money on this.

Classic question 4: Does the 1U server chassis need a front USB interface?

USB front is not very meaningful for rack-mounted servers. If it is put on the shelf, it is basically useless. Friends who have been to the telecommunications room know that 1U rack-mounted servers are usually placed in a cabinet, a stack of The 1U server is stacked high in the cabinet without a monitor or keyboard and mouse, etc. Therefore, when you want to debug the server, you always push the cart (there is a monitor, keyboard and mouse), walk to the back of the cabinet, and open the door. Plug in monitors, keyboards and mice from the back for debugging, so for rack-mounted servers, it is just the opposite of ordinary PCs. We hope that various interfaces will be concentrated behind the server as much as possible, because we can only open the back door of the cabinet for debugging.