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This page will not include specific motherboard component analysis like the Chipset or the BIOS because specific informations pages will be available about these topics right on this site. I will mostly concentrate about how to do to diferenciate a good motherboard from a not so good one.
Important Points to Consider
The Overall Board Construction quality is not easy to evaluate. Most of the time when someone buy a board he does'nt have the possibility to see it before to buy it and this is especially true in the case of mail orders. So, i will give you some tips to help you differenciate high quality boards from low quality boards.
The printed circuit board can be determined by the number of fiberglass layers used in its composition. The higher the number the stronger and the more rigid is the board. Usually we can find 2 types of circuit board the first being the cheaper one with only 4 fiberglass layers and the later being the best one with 6 fiberglass layers. The more layer there are the more rigid the board will be thus ensuring that it wont break when you will have to insert add-on cards or add memory modules. Boards with more than 6 fiberglass layers exist's but i'm not awaree of boards with more than 8 layers, besides i must admit that 6 layers circuit board are allready difficult to find.
The solder quality. Soldering the components on a printed circuit board is a process that is relatively simple but some very precise conditions must be respected to avoid cold solder spots. A cold solder spot might not give problems for a good period of time and all of a sudden make a board allmost useless a few months later.
The way to check for a cold solder spot is to use a good magnified lense and closely look all the solder point to see if every of them are well covered and if they all have a very shiny look. A well soldered component allways have a very shiny look so if you see a component pins unevenly covered with solder and having a dull gray appearanceyou should be very suspicious of the quality of this board and reject it! This may sound a foolish idea to do but even though it's a very annoying task because of the thousands of solder points to check its the only way to make sure you wont get problems when the warranty of the board has expired!
The socket connectors for the CPU, the cache memory, the extension slots, the disk drives and the power connectors are another imnportant point to check. The socket connectors quality used is varying very much from a mothrboard manufacturer to another and while some of them only use high grade connectors some others are using cheaper connectors. One of the best connectors brand available on the market is manufactured by Amp inc. so you must at least have this brand of connector for the CPU socket. Of course if you could also find them for the memory sockets and the extension slots it would be a good plus but odds are that there are very few boards on the market using them all the way around. Agood rule of thumb is to look for gold plated socket connectors because they defenitely are of higher quality so one can expect a better overal construction quality from gold plated socket connectors.
The capacitors. Todays electrolytic capacitors quality is very uniformised and i could'nt realy tell you of any very bad brand. However, a good rule of thumb can be applied to make sure that your motherboard capacitors are not likely to generate problems and its by looking at their voltage ratings. There are 2 main voltages circulating on your motherboard and they are respectively 12dc volts and 5dc volts so these are the two highest voltages that the capacitors will be faced with. So, if you see a 6vdc capacitor it could mean that it is plugged on a trace where 5dc volts is circulating and this is not good because its pretty close from the maximum rating of the capacitor and 10vdc would be more suited while a 16vdc would be optimal. However if you only see 16vdc capacitors of the board this can be good news as well as bad news. Its good news because it mean's that where there is only 5vdc circulating the use of a 16vdc capacitor is a good thing but if there is 12vdc circulating its a bit tight and a 25vdc capacitor would have been much better. The potential problem is that the electrolitic solution used inside of the capacitor tend to dry wile time is passing by and this make's the capacitor loose its property, so, according to this, if the capacitor is used too close of its maximum ratings there is no room for a good security margin and when the capacitor will reach a point where it can no longer tolerate this situation the isolation envelop between each of its layers will break and cause a short circuit wich will destroy the capacitor and probably many of the surrounding components if not all the motherboard itself. In résumé avoid motherboard using 6vdc capacitors and look for 16vdc and 25vdc capacitors.
A last word about capacitors would be concerning the "Tentalum" type capacitors wich look like a water drop. These capacitors are very unpredictable and very unstable and i would highly recommend to avoid any board using this type of capacitors. While i have been working as an electronic technician i have seen countless problems generated by this type of capacitors compared to much much less problems caused by standard electrolytic capacitors, the ratio i observed would give about 25 to 1. The electrolytic capacitors can be distinguished by their barel shape while the Tentalum capacitors looks like a baloon, a water drop or a pear shape if you prefer.
Finally, i would like to mention that capacitors are very heat sensitive devices and if you want to enhance their life expectancy you must ensure a good colling of your computer case. Most of the time large capacitors are used very close to the voltage regulators and this is not good at all because of the heat generated by these regulators so i will never say enougt that computers need a good cooling if you want to avoid problems. But, what exactly is good cooling are you asking? A simple answer would say that its not the kind of cooling that come's installed by the manufacturer of your computer! A fan can have a good CFM (cubic foot air minute) production and be unefficent because of restrictions caused by the lack of venting holes in your computer case so before to buy a case make sure that there are sufficient venting holes so the fan wont be restricted in its work. Next try to look for the fan CFM rating and if it's under 25 CFM then you will have to change it. Anyway most of the time the stock installed fans are of the bushing type and this type of fan is just nothing but crap so look for a ball bearing fan and try to find something between 30 and 50 CFM but not much higher because the higher the CFM the higher the air flow noise will be so a good balance between the CFM capacity and the noise should be established.
This is probably the most important point to verify when choosing a new motherboard. I saw countless peoples being stuck with motherboards not allowing support for the allready available technologies that i could never emphasize too much on this point. You must make sure that the motherboard you just about the buy is at least supporting all the available technologies even if you dont use all of them at this moment. For instance one of my friend bought about 3 weeks ago a brand new computer system without telling me so i just could'nt give him any advices. Now he is stuck with a VX chipset wich does'nt allow for the new Ultra DMA hard disk drives. He's been sold this system with only EDO memory installed while he could have asked for SDRAM memory wich would have give a much better performance system, and so on , and so on. If this person would have been better advised he will probably have never bought this system and would have choosen at least a computer with a motherboard allowing for the Ulta DMA hard disk drives with SDRAM memory instead of EDO memory.
So, in order to to help you make the best possible choice i listed down
below the most essential things to verify before th choose a motherboard.
This may make no differences for you if you only consider to use Intel's CPUs but you might be tempted to try another CPU one of these days so make sure that the motherboard also allow support for AMD and Cyrix CPUs!
All Chipset brand are not alike and do not support all the same features. Some Chipset only support old memory types while others ones offer support for a large variety of memory types including the newest memory developped. Some chipset also have limited memory caching capabilities while other can cache over 1 gigabyte of memory. They also do not offer the same hard-disk drive types support capabilities as well as they do not also support all the same BUS types!
To better understand the importance of choosing a motherboard with the right chipset i strongly recommend that you read my Chipset Information Page.so you can understand all the subtilities of this very important component installed on the motherboard.
Voltages regulators come in two flavors, the so called "Passive" voltages regulators and the 'Switching" voltages regulators.
First of all allow me to clear a very popular miscomception, the so called "Passive" volatges regulators just do not exist!
A voltage regulators is not a passive device either it works in the switching mode or not so all voltage regulators are effectively active devices unless it is build from resistors and capacitors like we used to do in the good old years but the this type of circuit was called a voltage divider not a voltage regulator. So the exact term to use when speaking of non switching volatges regulators is "Analog" voltages regulators.
There are two important differences about Switching and Analog voltages regulators and it is in the way they use to work while regulating the ouptput voltage. The Analog volatge regulators is working on an allmost constant load of current and voltage so it generate much more heat while Switching voltages regulators use a high frequency signal that sweep them from a non comducting state to a full conducting state and this process is contributing to generate much less heat.
The main problem with Analog voltage regulators is the heat. The heat generated by this type of regulators must be efficiently dissipated and this require the use of large heatsink surface and a good air flow to ensure proper working conditions. The Switching voltage regulators do also generate some heat but much much less than its counterpart so cooling of this type of regulators is much less complicated but also required.
However, other than the heat problems there is another very important thing to consider between these two types of regulators and it is the noise problem. Analog voltages regulators do not generate noise because they do not have to go from a state to another while working. However, this is not the case of the Switching voltage regulators. Because Switching voltage regulators are constantly sweeping from one state to another they do generate residual noises and if this noise is not efficiently filtered it can easily corrupt the motherboard data. Furthermore, the high frequency signal used to drive the Switching voltage regulators can also radiate by itself and contribute to some data corruption so great care must be taken when using this type of regulators. Switching voltage regulators are much more tricky to use and some cheap design may conduct to some very strange motherboard behavior. A good proof of it is your computer power supply. Maybe you've never noticed but all computer power supply are located at the most far end physically possible from the motherboard and they are allways enclosed in an allmost 100% shielded casing specifically to ensure that no high frequency signals will radiate out of it and this is specifically because these power supply are allways using Switching voltage regulators! So you now understand my suspiction when it's time to consider the use of Switching voltage regulators directly implemented on the motherboard!
Finally, you must make sure that whatever voltages regulators types are used that they can adequately support the extra current consumption required by Cyrix and AMD processors wich can be in excess of 2 ampere compared to Intel CPUs. A good way to do it is to located the regulators (Wich usually are large flat devices using 3 pins) and note their parts numbers then go to an electronic parts store and ask how much current is supporting this device. Electronic parts stores allways have data books they can use to get allmost any electronic component devices specifications.In the case of Switching regulators this is a bit more complicated because the regulators are often looking very different. However these regulators are allmost allways located close to the CPU and around a 1 1/2 inch diameter (or about) round ferrite torroidal core so look around this area and note the 3 or 4 largest parts and again go to an electronic store to help you get the specs.
The support for MMx enhanced CPUs is also very important because allmost all new CPUs offered on the market are actually offering this new feature so it'll be a good idea to make sure that it'll be supported. This support is related to the different voltages plane offered by the voltages regulators installed on the motherboard.
The more they are the better it is! However you should also check for the possibility to use extra long add-on cards in the ISA slots because most of the time this is not possible on many AT format motherboard.
It is common for 2 or 3 ISA slots to be blocked by the CPU, and usually none of the PCI slots are also blocked so only a visual inspection of the motherboard will reveal this problem. If you cant see the motherboard before to buy it then the best way will be to go to the manufacturer web site and try to see if there are pictures of this motherboard available. To easily locate allmost any motherboards manufacturers use my Manufacturer Listing and use the Hardware sorted listing to locate the motherboard section.
The motherboard Form Factor
There are two commonly available motherboard form factor available and these are the AT format and the ATX format.
These different motherboards format are not compatible to each other because they inherit of a very different mechanical structure as well as a different electrical structure. A baby AT motherboard just cant be installed inside an ATX case as well as an ATX motherboard cant be installed inside an AT casing.
So you must make sure that the motherboard you will buy will not only fit in your casing but that it will also be compatible with the power supply as well as with the power connectors.
This will be indicated by the type of Chipset used on the motherboard so check for the Chipset and it'll tell you all you need to know about what type and size of memory modules are supported. You can also have a look at the Motherboard manual if possible. The maximum size of memory modules would also be indicated in the manual and it would be very wise to check for it because many motherboard do not allow for memory modules larger that 32megs. The amount of cacheable memory is also function of the Chipset. For example the Intel 430TX chipset does'nt allow for more that 64megs of memory to be cached and when one goes over this limit the overall performances of the computer can drop by as much as 20%!!! Again you can use my manufacturer listing to go to the web site of your motherboard manufacturer to check if these informations are availabe.
Wether or not you want to overclock your CPU the maximum bus speed allowed by your motherboard can give you a good indication of its overall quality. Its a clear fact that motherboard that only support 66mhz of bus speed are out of consideration. A good motherboard should at least support both 66mhz and 75mhz bus speed while support for 83mhz is a defenitive plus and support for 100mhz bus speed is like a cherry on the sunday! The highest bus speed possible of a motherboard can be interpreted as a relative indication of its inherent stability so allways go for the motherboard claiming the
highest possible bus speed.
Dual or even quad CPUs motherboard are readily availabe but before to go for this kind of board you need to have the right Operating System installed on you HDD. DOS, WIndows 3.xx and Windows 95 are in no way capable to gain profit of a multi-processor environment. You will need at least Windows NT to handle a dual CPU motherboard while only Windows NT Server can gain profit form a quad CPU system. Linux and OS/2 can also handle multiple processors to some extends.
Anyway none of these multiple processors environment will give you gains of 100% when doubling the number of CPUs in use and the performances gains tightly depends of the applications used. Multi-threaded applications are more likely to gain profit from a multi-processors environment. If you happen to constantly run many CPU intensive applications at the same time you could also get some interesting performances increases but again performances gain will vary depending of the applications in use.
Wheter you want to go or not for an AGP slot equipped motherboard depends of your own preferences but you must be aware that allmost all Graphic cards manufacturer are now offering AGP Graphic cards and many of these cards give the highest graphic performances observed until now.
Let me explain to you what is the AGP slot. First of all AGP stands for Accelerated Graphic Port so it essentially means that this slot is specifically dedicated to the graphic (video) card.
The Accelerated Graphics Port (AGP) interface is a new port specifically designed to allow AGP based graphic card to perform with much better performances than the PCI based graphic cards.
The AGP allow a whole bunch of new features to be supported by the graphic cards. Amomg these new supported features you have an access to the computer main memory to store specific graphic informations. This is supposed to provide a higher bandwidth but i doubt very much about it because this memory is allready constantly being accessed by the computer hardware so it'll have now have to be shared with the AGP card to store z-buffering, and alpha blending informations so i dont see how this could realy dramatically improve performances!
AGP is also supposed to give 4 times more bandwidth than the PCI based graphic cards but actually there is only the 2X mode being offered. The AGP 4X mode is suppoed to be availabe by the end of 1998 tough.
Actualy the PCI bus is capable of sustainning a data transfer rate of up to 133 MB. AGP on the other hand using the same 66MHz bus speed can go up to 533 MB because it has the ability to transfer data on both the rising and falling edges of the 66MHz clock while using the 2X mode but remember that doing this it shares the computer main memory so the real gain just cant be this high and probably will look like something around half of this figure! In my opinion AGP will realy began to speak seiously when 100mhz bus based motherboards will be available!
While the PCI bus will continue to be the most used interface architecture for peripherals interconnection the AGP is sure very promissing in terms of new graphic performances enhancement but in my opinion it is just beginning to give interesting performances over the PCI based graphic cards so care must be taken not to go too fast to this new graphic card technology.
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