Desktop PC Case Form Factors…. Custom solutions and modding
Nowadays, ready-made computers can be bought at most hardware stores. But this approach does not suit everyone. Assembling from components to order allows you to make a system unit that suits the tasks of a particular person. Moreover, such a computer will be unique.
Usually, when making a configuration system unit, the body is chosen, as they say, "for delivery." Yes, this approach is true for office PCs, where the goal is to save money. Earlier, when computers of the modern ATX format only appeared in Russia, most cases differed only in the height and design of the front panel, people did not even think about the choice at all. The most popular format was Tower (regular tower). Gaming and powerful configurations were assembled in Full-Tower (the same tower, but one and a half times, or even two times higher), most often with a door on the front wall. Horizontal, so-called desktops, on which there were monitors, gradually disappeared from sale. Initially, all cases were "just gray boxes", then silver and black colors came into fashion.
If someone thinks that everything has remained the same, he simply has not been in a computer store for a long time. Now on display cases you can find cases of all kinds of shapes, colors and sizes. And when assembling, for example, a small computer, it is the case that most often becomes decisive. Today's article will help you not to get lost in this diversity.
Midi-Tower and Mini-Tower sizes.
Despite the desire for miniaturization, the most popular are vertical midi-towers. Approximate dimensions: width 15-20cm, height 43-45cm. These enclosures can accommodate a full-size standard ATX motherboard, a standard-sized power supply, multiple hard drives and disk drives. The application is universal. The sizes are suitable for both high-performance computers and office PCs. Expansion slots are most often 6. However, such a number of expansion cards is not needed modern computers, especially office ones. MicroATX motherboards immediately have built-in sound and network cards, and the processors have an integrated video core. Thanks to this, you can save on dimensions - use a mini-Tower case. It is lower than the midi-Tower (about 33-35cm in height), however, and it will turn out to be a little bit to install in them: 1-2 optical drive, 1-2 hard disk and approximately 4 expansion slots.
Tower PSU Presence and Location.
Often, cases of this format are equipped with built-in power supplies. In the case of an office computer, the hardest work for which is spreadsheet editors and Email, you can use simple cases with a built-in power supply, 300-450W. A multimedia PC, as well as a mid-level gaming PC, can get by with a 500-600W unit preinstalled in the case. Most often, this solution allows you to save money, but for serious workstations, or powerful gaming computers, this will not be enough. Power supplies built into cases, usually of simple series with a minimum set of connectors, will be difficult to connect to a powerful video card, or a large number of hard drives.
Micro-Tower and Slim-Desktop sizes.
What if we made the body even smaller? This is how Micro-Tower and Slim-Desktop appeared. The former are lower than the mini-Tower, and there is only one 5.25-inch drive bay. The latter are narrower than standard towers. The width can be reduced by positioning the power supply vertically, sometimes even at the front. The optical drive bay is also located vertically, or is absent altogether. This allows the body to be positioned both standing and lying, which is why the title contains the word desktop. In such cases, computers are usually assembled with low power consumption, and, accordingly, heat dissipation, since air movement in them is difficult.
Desktop standard size.
Full-Tower, Ultra-Tower and Super-Tower sizes.
Non-standard solutions and modding.
What if you want something non-standard? It is possible to purchase a body of your favorite color that will fit into the design of a room or office. For example, pink. If your favorite color is black, the variety of cases increases, of course, but manufacturers have not considered it the only one for a long time. The choice of materials is not limited to steel - various are used in the decoration. Budget segment. In this range, there are cases for office system units with 350-400W PSUs, you can also find cases for HTPCs with 200W PSUs with support for mITX-format motherboards. The number of ports, expansion slots and pre-installed fans is minimal.
3500r - 6000r. Cases with a 450-500W PSU, or mITX cases with a 300W PSU, can be assembled in them already multimedia computer for home, but some interesting solutions as in the previous group, there is no need to wait.
6000 RUB - 13000 RUB Here you can already find interesting options, closer to the upper border - even Full-Tower cases with a window on the side wall, adjustable fan speed and 600 W power supplies, in which you can easily assemble, for example, a media server with a large number of hard drives. Modern video cards, even powerful ones, do not have as high power supply requirements as before, which means that a gaming computer of an entry, middle, and even above average level will feel good in cases of this range. Of course, you should pay attention to the number of case fans, one on the front wall and one on the back - the required minimum. However, the missing quantity can always be purchased separately.
Housings without built-in power supply.
900 RUB - 2500 RUB First level. Office cases, as simple as possible black boxes. However, the case of the upper price range (2000r-2500r) when installing a powerful power supply unit does not interfere with using it at home. At the same time, do not forget about compatibility with components, for example, gaming video cards.
2500r - 8000r. Average level. Here is everything that was described in the article. And ordinary towers, and cubic cases with interesting color schemes, and aluminum cases for HTPC, and Full-Tower for a system of any capacity.
8000r - 22000r Top level. The most thought-out cases in terms of design, materials and cooling. Suitable for the most demanding users. It is in such cases that "top-end" systems are assembled.
From 22000r. Premium level. There is no upper price limit. For those users who are not ready to put up with the fact that someone will have a similar case. They are often produced in small batches, from unusual materials. Have a memorable design.
Introduction Over the past few years, the market personal computers has changed a lot. Large number of users using computing technology for surfing the Internet or as a home entertainment center, the PC has come to be treated like a common household appliance. As a result, the structure of demand for all computer components has changed dramatically. Many suffered from this, including manufacturers of components.
With the number of PC enthusiasts gradually dwindling, motherboard manufacturers have started to face the decline in demand for their high-end products. On the other hand, the increasing integration of sets system logic began to lead to the fact that most motherboards from different manufacturers began to closely resemble each other in their characteristics, preventing the manufacturers of high-end motherboards from standing out among their kind. In this situation, those of the motherboard manufacturers who do not have large OEM orders began to feel somewhat insecure in the market, since the production of cheap solutions alone “will not go far”.
One of the ways out of the impending crisis for motherboard manufacturers was to diversify production and offer completely different types of products. As we can see, many of the former motherboard manufacturers started making video cards. Some have entered the server market. Some manufacturers began to offer laptops or PDAs. Other manufacturers began to manufacture and actively promote the so-called Small Form Factor (SFF) PCs. We will dwell on them in more detail.
SFF PCs are small computers designed for home or office use. They are united by their key feature, which follows from the name, namely, small size. At the same time, SFF computers have a number of other advantages over their counterparts, for example, reduced noise levels. But this is more a consequence than a cause. In addition, according to their design, SFF PC manufacturers try to make it look in such a way that in the eyes of an inexperienced user looking at an SFF PC, the line between a computer and any other household appliances is erased.
SFF PCs are supplied as barebone kits, that is, in the form of a kind of "skeletons" for creating ready-made systems. This is not surprising. While the production of special motherboards and cases is quite within the power of motherboard manufacturers at their facilities, they cannot produce processors or hard drives. Therefore, the classic barebone SFF PC includes a case with a power supply, a motherboard with an integrated graphics core, or a video card. However, the package contents of various barebones may vary.
Today in our laboratory was the first such skeletal set of Small Form Factor PC from the FIC company. Naturally, we could not deny ourselves the pleasure of testing it. Moreover, with its small size and quite "adult" characteristics, he won the sympathy of your humble servant.
Specifications and appearance
So, the laboratory received an SFF PC from FIC, Samba (SM) -1845 for testing.This skeleton kit, as the official specification says, is intended for building a home or office computer based on a Socket 478 Intel Celeron or Intel Pentium 4 processor with a 400MHz system bus. The motherboard used in the Samba-1845 uses the i845 chipset with support for PC133 SDRAM, and also has an AGP 4x slot that can accommodate slim-form AGP video cards.
To give the reader an idea of the size of the Small Form Factor PC, here is a photo of the Samba-1845, standing next to the traditional mini-tower from Inwin:
Note that Samba (SM) -1845 allows both vertical and horizontal installation of the system unit.
The details of the Samba-1845 specifications are as follows:
Socket 478 support Intel processors Pentium 4 and Intel Celeron with 400 MHz bus frequency;
Intel 845 chipset with ICH2 southbridge;
Two DIMM slots supporting up to 1GB PC133 SDRAM;
AGP 4x slot and two PCI slots;
AC97 audio codec CS4299 with SPDIF support;
One 3.5 "internal ATA-100 bay hard disk, one 3.5 "external bay for a standard 1.44 MB floppy drive, one 5.25" external bay for an external ATA-100 optical drive;
Integrated 10/100 Mbit Ethernet controller Intel 82562;
Delta 150W power supply;
Four USB 1.1 ports (two on the front and two on the back);
Two IEEE1394 ports (one four-pin and one six-pin);
Two PCMCIA Type II slots;
Dimensions 310 (width) x 360 (depth) x 93 (height) mm.
In addition, the Samba (SM) -1845 package includes a 3.5 "1.44 MB floppy drive, as well as a slim video card from FIC based on the GeForce2 MX 200 chip.
The front panel of the Samba-1845 contains the front parts of the drive and CD-ROM bays (the front panel of the CD-ROM is closed by a door); two PCMCIA Type II slots, which can be used to connect additional devices to a computer, traditionally focused on use in laptops; a power button and several connectors covered with a latch. Pulling back the latch reveals two USB 1.1 ports, a six-pin and four-pin Firewire ports, and a microphone input. These are the features of Samba-1845, facing the user face.
Expanding Samba (SM) -1845 180 degrees, we find a power connector, one serial and one parallel ports, an RJ45 network port, two more USB 1.1 ports, PS / 2 connectors for connecting a mouse and keyboard, audio input and audio -output, as well as optical SPDIF output. In addition, there you can find D-Sub video output from the video card supplied with Samba (SM) -1845. As you can see from the rear panel, Samba (SM) -1845 allows the installation of both additional cards extensions.
After removing the cover from Samba (SM) -1845, it turns out that in order to turn this skeleton kit into a full-fledged SFF PC, you need to install the hard drive and CD-ROM drive, as well as the processor and memory. In addition, Samba (SM) -1845 will allow, at the user's request, the installation of two additional PCI expansion cards, for example, a modem and a USB 2.0 controller, however, this set's capabilities for expanding the capabilities will not be exhausted yet. Support for two PCMCIA Type II slots allows connection to almost any Samba (SM) -1845 external devices.
Motherboard
Unlike other barebone manufacturers, FIC uses a dedicated motherboard for its Samba (SM) -1845, not a commercially available integrated board that is sold separately. However, this is understandable. The Samba (SM) -1845 board has a number of unique features, which we will discuss below.
The motherboard of the same name with the SFF PC itself is based on the i845 chipset and supports two DIMM slots for PC133 SDRAM. Unfortunately, this is what should be recognized as the main drawback of Samba (SM) -1845: the board does not allow the installation of any more modern types of memory, as a result of which the performance of a system built on Samba (SM) -1845 will be significantly limited by the type of memory used. The decision of the Samba (SM) -1845 designers looks even stranger, if we take into account the fact that PC133 SDRAM and DDR SDRAM are now practically the same prices on the market. Therefore, the only justification for the designers of this SFF PC is that the i845 chipset with SDR SDRAM support is somewhat cheaper than its DDR counterparts.
Also, the choice of the i845 chipset as the basis for Samba (SM) -1845 led to the fact that although the board supports Socket 478 processors, it does not have official support for the 533MHz bus. So, if you follow the instructions, you will have to install either Celeron or Pentium 4 with 400MHz bus in Samba (SM) -1845. However, as a test has shown in practice, Samba (SM) -1845 can work with more modern processors with a 533MHz bus without any problems.
As a plus of the applied solution, it should be noted that the motherboard supports external video cards, and this makes it possible to upgrade not only the processors, but also the video subsystem in the future.
External slots on Samba (SM) -1845 are made on an additional riser card. Thus, the FIC engineers were able to achieve a significant reduction in the height of their SFF system. The riser card used in Samba (SM) -1845 has two PCI slots and one AGP 4x slot.
The choice of the i845 chipset as the chipset also led to the fact that the board uses a somewhat outdated ICH2 south bridge. However, its major drawbacks can be attributed only to the lack of support for the USB 2.0 protocol, which can be easily compensated for using external controllers if necessary, since Samba (SM) -1845 has free PCI slots.
As for the rest, the board supports the entire set of integrated devices implemented both through the chipset, which include AC'97 sound (CS4299 codec is used) and USB, and through external controllers, for example, two IEEE1394 ports.
Special mention should be made of the PCMCIA controller, thanks to which Samba (SM) -1845 has a truly remarkable expandability via PCMCIA Type II cards.
Note also that only one IDE channel is wired on the Samba (SM) -1845 board. However, given that the Samba (SM) -1845 system itself is not designed to be bundled with more than two devices, this fact does not seem like a big drawback.
The BIOS through which Samba (SM) -1845 is controlled is a regular Phoenix / Award v6.00PG with a minimum number of settings. Considering that this system is positioned for the market of home and office computers, the simplicity of its configuration is its undoubted and significant plus.
The video card included in the Samba (SM) -1845 kit is a regular GeFroce2 MX200 with 32 MB of SDR memory manufactured by FIC itself.
This video card allows you to get an entry-level video subsystem, which, however, can be quite successfully improved by replacing this video card with more modern ones. By the way, Samba (SM) -1845 can fit not only slim video cards, as required by the instructions. Some small video cards of the classic format can also be installed in Samba (SM) -1845.
Power Supply
I would like to say a few words about the power supply unit used in Samba (SM) -1845.
For its barebone, FIC used a small block from the Chinese company Delta Electronics. Despite the low power of 150W, this unit is ATX 2.03 compliant and has an optional 12V cable for use with Pentium 4 motherboards. At the same time, given that only one hard drive and one optical drive can be installed in a system based on Samba (SM) -1845, and it is also not allowed to install video cards with high power consumption (due to the possibility of using only small video cards), the capacity is 150 Watts should be sufficient for systems built using very powerful processors, with frequencies up to 2.6 GHz.
Also, the unit has three additional power cables, as a result of which, after installation in the case of a floppy drive, CD-ROM and hard drive, there will be no free "tails" left.
The specified power supply unit has one small fan, which is intended, obviously, to cool the unit itself. Its power is clearly not enough to blow air through the entire case (which is clearly necessary, given the possibility of using Pentium 4 processors in Samba (SM) -1845).
Cooling system
In light of the fact that the SFF PC is by definition a small computer, traditional cooling systems cannot be used in it. Moreover, manufacturers are trying to make their SFFs as quiet as possible, so they try to reduce the number of fans in such systems. As mentioned above, the fan used in the power supply unit is intended only for cooling the unit itself. Therefore, a common solution for SFF PCs is a cooler that simultaneously cools the processor and exchanges air in the case with the environment.The solution chosen by FIC engineers for Samba (SM) -1845 cooling is simple on the one hand and originality on the other. The processor is put on aluminum radiator firm AVC, which is attached directly to the case with four spring-loaded bolts, and exactly above it is a large fan, which blows air out through the holes cut in the case cover.
Thus, not only effective cooling of the processor is achieved, but also of other system components due to the fact that the fan blows air not only through the processor heatsink, but also through the entire system.
In terms of noise, the system contains only one large and one small fan, which are less noisy. According to official figures, which are reported by the FIC company, the noise level of Samba (SM) -1845 does not exceed 30 dB. By the way, the large main fan located above the processor is low-speed and its rotational speed is about 2500 rpm.
Assembly
Having described the skeletal system from FIC, we will try to build on its basis full computer... The first thing you need to do is open the case. This requires a Phillips screwdriver - the Samba (SM) -1845 cover is secured with three screws. After removing the cover, the user sees the following picture:
After removing the bracket to which the fan is attached, the user has easy access to all system components. True, to mount the hard drive, it is necessary to remove the basket above the power supply, but this operation is unlikely to be laborious, since the basket itself is fastened with two screws, which can be easily accessed. On the positive side, the hard drive is not fixed rigidly in the basket, but through four rubber pads, also designed to reduce the noise level produced by Samba (SM) -1845.
The only question that may arise during the assembly process after installing the hard drive is CD-ROM drive, processor, heatsink, memory and, if necessary, expansion cards - this is how to connect a motherboard with one 80-wire cable, HDD and an optical drive, given that the disc and CD-ROM connectors are far enough apart and point in opposite directions. Fortunately, Samba (SM) -1845 comes with a specially curved IDE cable, which makes connecting IDE devices quite easy.
As a result, we get Samba (SM) -1845 assembled:
After installing the fan in place, the arrangement of the components in the system looks a bit cramped, however, that is why it is a Small Form Factor PC.
Note that during the assembly process it turned out that the DIMMs were marked incorrectly on the board and after assembling the kit, it refused to start. However, the cause of the problems was quickly found out, the memory module was rearranged, and after that everything went like clockwork.
So, the system is assembled, it's time to move on to the tests.
Test results
Before proceeding directly to the test results, I want to tell you about the unexpectedness that occurred during the preparation for testing. As it turned out, despite all the assertions of the specification, as well as the fact that the i845 logic set used in Samba (SM) -1845 does not officially support the 533MHz bus, our system successfully started with a Pentium 4 2.4B processor, designed to use this particular one. bus frequency. At the same time, the system actually operated at a Quad Pumped Bus frequency of 533 MHz. In this regard, it was decided to conduct testing with the Pentium 4 2.4B processor, since the behavior of Samba (SM) -1845 with such a CPU seems extremely interesting.As a result, the composition test system was as follows:
SFF PC Samba (SM) -1845;
Intel Pentium 4 2.4B processor (bus - 533 MHz);
Memory - 256 MB PC133 SDRAM;
Fujitsu MPG3409AH hard drive;
CD-ROM ASUS 32x.
During testing, the system proved to be extremely stable, there were no complaints about it from this point of view. The 150-watt power supply was also powerful enough to power the above system, even under the harshest conditions.
As a result, the following indicators were obtained:
| Test | Result |
|---|---|
| SYSmark 2002 | 211 |
| SYSmark 2002, Internet Content Creation | 291 |
| SYSmark 2002, Office Productivity | 153 |
| 3DMark2001 SE, Default | 1545 |
| Quake3 Arena (four), Fastest, 640x480x16 | 169.8 |
| Quake3 Arena (four), High Quality, 800x600x32 | 50.6 |
| PCMark2002, CPU score | 5797 |
| PCMark2002, Memory score | 4090 |
Actually, the results obtained are not surprising. Low results in 3D graphics tests are explained by the weakness of the video card used in Samba (SM) -1845 - NVIDIA GeForce2 MX200 with 32 MBytes SDR SDRAM. At the same time, the frequencies of this video card are 175 MHz on the chip and 167 MHz on the memory. In general, Samba (SM) -1845 is suitable for 3D games only conditionally.
As for the results in processor tests and in the SYSmark 2002 office test, it should be noted that they are inferior to the results obtained on full-fledged systems with a similar CPU, only by 10-15%. This lag is due to the low-performance PC133 SDRAM used in Samba (SM) -1845.
However, apparently trying to eliminate this shortcoming, FIC will soon start shipping a new version of its SFF PC, Samba (SM) -1845GL. This skeleton system will be based on the i845GL chipset and support DDR266 memory. However, due to the choice of the chipset, this time the system will not be able to use external AGP graphics cards, and the Intel Extreme Graphics integrated into the i845GL will be used. However, in Samba (SM) -1845GL it will be possible to upgrade the video subsystem by using external graphics cards PCI format, since in Samba (SM) -1845GL the number of PCI slots will be increased to three. Also, a new version Samba (SM) -1845GL will support and USB protocol 2.0 Powered by Capabilities south bridge ICH4.
Returning to the results of our testing, it is also necessary to note the efficiency of the cooling system used in Samba (SM) -1845. During work and stress tests, the processor temperature did not rise above 67 degrees, and the temperature inside the case was always below 37 degrees.
conclusions
Small Form Factor PC Samba (SM) -1845 looks like a good basis for a home or office computer in cases where this computer is not planned to be used for 3D games. As for the rest, the characteristics of Samba (SM) -1845 are such that this platform will be quite sufficient for use in almost any area where high computing performance of the system is not required. In addition, Samba (SM) -1845 is nicely designed and operates with very little noise.Unfortunately, with all the undoubted advantages of this solution, it should be noted that there is also a significant drawback of FIC Samba (SM) -1845. This barebone system lacks any support from the FIC. The company does not offer any new BIOS firmware nor new drivers for Samba.
Pros:
Stylish design and small size;
Low noise level;
Two additional PCI slots and support for AGP video cards;
PCMCIA Type II support;
Support for USB, IEEE1394, Ethernet and AC'97 sound;
Ease of assembly.
Minuses:
Work with PC133 SDRAM;
Low-performance graphics subsystem;
Lack of USB 2.0 support;
Lack of online support on the FIC website.
The article compares different types small form factor boards. Having made a choice in favor of computers on the module, the author explains why CoM is the most suitable for modern tasks and what are the features of the four CoM form factors, which are the de facto standards. And also tells you how to choose suitable module for your own project.
Representative office of Congatec AG, Moscow
The miniaturized form factor is not a new invention in embedded systems, but the need to reduce system size, weight and power has increased the demands on it, which has been embodied in a number of design solutions. Almost two decades ago, the PC / 104 board, with its small footprint (3.55 x 3.78 ″), revolutionized modular industrial computers. However, over the years, the concept of Small Form Factor (SFF) modules has led to the emergence of a hard-to-manage group of diverse platforms and so-called standards.
In general, SFF boards can be divided into three groups:
Single-board computers, SBC (single-board computer - English), all the functionality of which fits on one board without the possibility of further expansion;
Stack-type modules (the PC / 104 family belongs to them de facto), allowing to create devices of different levels - from a "simple" SBC to large trunk systems composed of standardized modules with arbitrary expansion options;
Computers on a Module (CoM), the main computing functions of which are concentrated in a standardized module connected to a standard or custom board.
Single board computers provide highest level vertical integration of boards and have the lowest cost, which is especially noticeable with a large number of them.
If the standard SBC does not meet the specifications, you need to create a custom board. Its development takes a lot of time and requires the work of a considerable number of highly qualified specialists due to the complexity of today's ultra-fast and miniature microcircuits - some with a grid step printed circuit board 0.600, 0.500 or even 0.400 millimeters. In addition to hardware, it is necessary to create BIOS (basic input / output system) and O / S (input / output subsystem) drivers. Today, in a highly competitive environment, companies strive to optimize R&D by focusing on the most important activities in order to be the first to reach the market.
Computer modules assembled as a shelf (or sandwich), namely in PC / 104 format, are advantageous, because whatever functionality is required, the device is always ready for sale. The development of "hardware" is simple and fast enough, since you only need to design a solution, buy modules and assemble them "in a stack". What are the disadvantages here? Systems built on the basis of PC / 104 modules are ideal for certain applications where a simple and robust solution is needed, and the requirements for computing power, graphics performance and heat dissipation are not so high. However, connectors and system are capital expenditures, and much of the ecosystem is focused on the ISA bus.
As technology has moved away from ISA and parallel buses over the past two decades, the once universal world of PC / 104 has fragmented into many variations and updates. There are now PC / 104, PC / 104 ‑ plus, PCI / 104, PCI / 104 ‑ Express, PCIe / 104, and SUMIT-ISM. This often leads to rather complex mixes and combinations in the ecosystem. What once seemed like a perfect advantage becomes a heavy burden when it comes to new product development. Many traditional products and components have worn out and are difficult to replace. Cooling can also be a daunting task due to the low design requirements for heat dissipation.
The current generation of CPUs, including Intel's Atom and AMD G-series processors, is the preferred and often the only choice for mid-range fanless devices today. In addition, in many applications, the total area of the PC / 104 card stack causes layout problems. Once the industry-leading form factor, the PC / 104 is no longer a trendsetter.
Thanks to the open international SMARC standard, computers on module (CoM) offer a wide range of performance and sizes, but only four form factors are true, de facto standards supported by regulatory authorities and major distributors. Let's list them (Fig. 1): this is ETX; its successful external update known as XTX; COM Express, which is the undisputed leader in the high-speed systems market today, and the relatively new Qseven, a form factor for low power, mobile and ultra mobile CoM applications.
Rice. 1. Evolution of computers on a module from the ETX form factor to Qseven
Together, these four form factors have incorporated everything typical benefits computers on the module. While most companies do not qualify for the latest computer technology with their ultra-thin pins and very EMC-sensitive high-speed signals, the computers on the module offer the most powerful tools to help you tackle the most difficult projects. These devices come fully equipped and guarantee a short development period. The split into two parts - common (CoM) and dedicated (main board) - makes it easy to scale and upgrade options, and also provides a tailor-made platform when it comes to size and placement of the wireless I / O connector. Go to newest computer technology with less power consumption and more processing power, it's as easy as replacing a computer module. Due to the nature of CoM, modules of this format are found in an almost limitless number of applications. With PCs on module, OEMs can be confident of tomorrow with multiple vendors, performance scalability, a platform that meets the latest requirements, and faster time-to-market. All of these advantages result in a more competitive end product in the market for OEMs.
Features of the four CoM form factors
Introduced in 1998, Embedded Technology eXtended, or ETX, became the first de facto standard in a series of CoM form factors. It retains the same I / O system, supports PS / 2 and board size 3.7 x 4.5 ″ (95 x 114 mm). ETX became the approved standard in 2000. Due to its maximum possible TDP (heat dissipation requirement) of 40 watts, it is used mainly in the industrial segments of the computing and automation market. From other industries where large installed systems based on computer modules of the ETX form factor, one can name medicine, transport and games. Together with the PC / 104 format, ETX is the oldest recognized standard among small form factors with unlimited ISA support. Currently, ETX modules are used mainly in legacy projects where it is necessary to support the ISA bus, which is more than twenty years old. With Intel's 855 chipset being discontinued today, ETX modules are equipped primarily with Geode, VIA or Atom processors, and the latest ETF modules are equipped with AMD processors G ‑ series that offer full graphics and increased CPU performance.
The XTX form factor, introduced in 2005, is an upgrade to ETX and is fully compatible with it. It features native SATA support (four ports) and four PCIe routes replacing the ISA bus on the fourth connector. This boosts I / O performance up to 2GB per second per route, enabling the latest high-speed motherboard interfaces. If ETX compatibility is required but ISA bus support is not required, then XTX is the best option. The HTX is a low-cost upgrade from the ETX form factor to modern high-performance platforms outside of the 855 chipset, as well as a gateway to powering a dual-core processor. ETX modules find applications in areas such as industrial computing, automation, medicine, transportation and gaming.
COM Express
COM Express was introduced as a standard by the PICMG * consortium in 2005. The main goal was to create a universal, scalable CoM standard free from legacy boards. The dimensions originally determined by PICMG were 3.7 x 4.9 "(95 x 125 mm) for the main boards and 4.3 x 6.1" (110 x 155 mm) for the extended ones. At the request of a large group of COM Express product manufacturers, an additional size of 3.7 x 3.7 "(95 x 95 mm) was introduced - compact, approximately the same as that of the PC / 104 board (90 x 96 mm). In addition to a new connector layout and several sizing options, the COM Express board comes with a number of important new features including: six PCIe routes, a PEG port option (composed of sixteen PCIe routes), SDVO interface, Gigabit LAN, and 5 to 12 power supply voltages. Q. Heat dissipation requirements (TDP), formerly a maximum of 40W (ETX / XTX), have been increased to 137W, including the most powerful high-performance processors and graphics chipsets. Released from the junk promoted by PICMG, COM Express has become the most popular CoM standard with the richest ecosystem and supported by vendors. For computers on the module today is provided wide choose embedded x86 processors ranging from low-power single-core Atom to high-performance quad-core i7. COM Express form factor modules are used for powerful gaming computers, high-performance medical equipment and digital signage, for industrial computers, automation, telecommunications, in transport and in terminals for payment with plastic cards in retail outlets.
The newest of the CoM standards. It was created in 2008 to support small low power devices, mobile and ultra mobile applications. The board size (Figure 2) is only 2.76 x 2.76 ″ (70 x 70 mm), no expensive board-to-board connector is required, rather an inexpensive but nonetheless reliable 230-face connector used in the MXM card slot which is widely used in mobile video cards. The heatsink is limited to 12W and the specified 5V allows mobile device work efficiently on two lithium batteries. Qseven supports more modern I / O buses, including up to four PCIe routes (no plug) with graphics supporting two ports - LVDS and SDVO (shared with an HDMI / display port). Qseven supports CAN interfaces, SPI, LPC and SDIO to guarantee maximum flexibility for mobile applications. Qseven is not only x86-based platform, it is also defined and supported by ARM. Highly useful function- Common Embedded Application Programming Interface (EAPI) for industrial applications such as watchdog, I²C bus, display dimming, BIOS storage, and reading system temperatures. The form factor finds applications in handheld and ultra mobile devices, computer panels, entry-level games, simple medical equipment, simple digital equipment, industrial computers, automation, in transport, in mobile applications for terminals. The Qseven format is suitable for any battery-powered or PoE-powered application, i.e. powered over twisted pair on an Ethernet network.
Oddly enough, but often before buying a new computer, people do not always think about the size and type of future PC (form factor). Most often it falls on the shoulders of sellers who are not always interested in the needs of the CLIENT, to put it simply - which case they got - they put it in that one ... However, this parameter is often important, both for the user and for the computer itself. How important is it? A lot of important parameters depend on the PC form factor (and on the correctness of its choice, of course ...): usability, noise level, case temperature, and hence follows: "health" of the components inside (primarily hard drives - which store your information - and this, as you know, is the highest value), convenience of work, etc., etc. ... So, how to choose the right size of the system unit of the future PC?
To begin with, I propose to consider them in more detail in turn:
In the beginning, it must be said that the size of the PC is not only the size of the case itself. The size of the case must also correspond to the dimensions of the components - the motherboard, first of all, the video card, power supply and other devices. For example, you cannot put system board ATX format into a miniTower case, or a video card like GeForce 9800GTX into the same case - it simply won't fit. And if it fits, it will be so hot that the small space will not allow efficient heat dissipation, and overheating will threaten all devices ...
So, let's look at the form factors of the cases - their size can be said to be directly proportional to the capabilities of the future PC. it determines the size of the components that can fit into it. And modern components are often large (for example, powerful video cards). Therefore, in a sense, we can give this advice: the more powerful the PC is planned, the larger the case ...
Full Tower: Dimensions of such a case: width 15-20cm, height 50-60cm. This case has 4 to 9 bays for 5.25 "devices (example: DVD-ROM drive), has 6 to 12 bays for 3.5" devices (example: hard drive), has the ability to install seven expansion cards (for example, TV tuner, sound card). This case also accommodates a full-size system ATX board(we will talk about their sizes later). Simply put, this type of case is the largest, and the capacity of various “hardware” is enormous. But here, of course, it all depends on the motherboard - how much it allows you to connect hard drives, expansion cards (which then find a place for themselves in the spaciousness of the case), etc. Application: Mainly for powerful computers focused exclusively on high performance, because such system blocks contain a lot of fast components, which are known to generate a lot of heat, and in such a large case, cooling is not difficult.
Mid Tower: Perhaps the most common size among household desktop computers... Its dimensions: width 15-20cm, height 43-45cm. These chassis can accommodate a full-size ATX motherboard, a full-size power supply, multiple hard drives, and quite a few hard drives. Application: We can say - universal. Sizes are acceptable for both high-end PCs and the average medium home computer... The space inside the chassis allows air to circulate within, usually without obstructing the cooling of the chassis and devices. I recommend it for building PCs - if your PC size requirements are common, and if you don't need a computer “on the shelf”.
Mini Tower: Mostly common in the office computer sector. Due to their small size (width 15-20cm, height 33-35cm), they allow you to install a little: (1-2 optical drives, 1-2 hard drives and about 4 expansion slots) and devices of average or lower performance. Firstly, because of the size, and secondly, because of heating. There is little space in such a case - and therefore the requirements for the temperature of the devices are higher, so that the nasty noise of the fans and overheating of the devices are not created. But in such a case, you can fit components that are quite enough for office work with text, presentations and spreadsheets.
Mini PC (Small Form Factor): With their dimensions (width 20 cm, height 18-23 cm) they can accommodate a maximum of 2 expansion slots, few hard drives and imply a compact power supply. This assumes that the user will mainly use the components built into the motherboard (which, by the way, is also small) such as integrated video and sound. By appearance these enclosures resemble household appliances... Their use - as office PCs or as the basis of a home theater. Cooling is not an issue here, since there are very few devices, and they emit a little heat by their intended purpose.
There are also form factors. Micro PC(which have even smaller dimensions compared to Mini-PCs, but because of their size have even greater limitations) and desktop (horizontal cases located on the table), but they are less common and you are unlikely to have to mess with them.
So, we looked at the form factors of the cases. I hope - you will choose something suitable for yourself. If not, you can seek individual advice.
In the following articles from the cycle of form factors, we will generally consider the form factors of the components of the system unit and other devices.