Hardware of PC

How to buy PC ?


What do you want to use your computer for?


Like in any other purchases, you have to answer the question: " For which purpose do you buy PC? " It' s silly to buy a machine in the value of 40 000 SK when you want to surf on INTERNET or listen to MP 3 music. There are some different variants:

1a. Home-users

These people may have the computer at work, or their children at school. They want to have an access to INTERNET & E-MAIL and utilize some more pretentious aims. Their eyes start to shine when they find out that it is possible to play a music CD on their PC composition and their computer can become next HI-FI stereo.
Exactly these users are the targets of computer sellers, because their knowledge is very poor. The majority supposes that PC is only a case, monitor and a keyboard.







1b. Half-professionals

The second level users of PCs have a stable access to them. Of coarse, they use INTERNET and have some hobbies for which they buy a computer: composing music, digital photographing or playing games. They know quite good, which component it should contains. Unfortunately, their decision are often based on advertising slogans and wrong advices of their friends.








1c. Professionals

Finally, the third group is made of pure professionals. They have PC for earning money and because of that fact they require the best performance and 100 % reliability. They will invest a lot of money to get corresponding quality.
These people sacrifice high amount of money into hi-tech machines. They know exactly what they want to buy, but many times they don' t receive adjacent product.







Basic configuration


When we talk about the most important parts of the computer, we can consider these three as the core: CPU (central processor unit), main-board and RAM (random access memory). 2. Processor

The CPU may be a single chip or a series of chips that perform arithmetic and logical calculations and that time and control the operations of the other elements of the system. Miniaturization and integration techniques made possible the development of the microprocessor, a CPU chip that incorporates additional circuitry and memory.



Most CPU chips and microprocessors are composed of four functional sections: an arithmetic/logic unit, registers, a control section and an internal bus.

The arithmetic/logic unit gives the chip its calculating ability and permits arithmetical and logical operations. The registers are temporary storage areas that hold data, keep track of instructions, and hold the location and results of these operations.
Basicly, we have only two possibilities: INTEL & AMD. The third- Taiwan company VIA with chips C3 is not the real alternative. The basic measurement of quality of CPUs is their frequency. In this times the common processor works at the speed of about 1 GHz. But also CPUs
with speed of 2.5 GHz are available. 3. RAM

Computer systems can store data internally (in memory) and externally (on storage devices). Internally, instructions or data can be temporarily stored in silicon RAM chips that are mounted directly on the computer’s main circuit board, or in chips mounted on peripheral cards that plug into the computer’s main circuit board. These RAM chips consist of millions of switches that are sensitive to changes in electric current. So-called static RAM chips hold their data as long as current flows through the circuit, whereas dynamic RAM (DRAM) chips need high or low voltages applied at regular intervals—every two milliseconds or so—if they are not to lose their information.





Memory circuits are very important parts of PC composition. They determine the speed of giving the data to CPU and greatly influence the whole performance. Contemporary, there are 3 moduls available: old, low-end, but cheap SDRAM, from them coming quick and modern DDR SDRAM and finally revolting RDRAM.



4. Main-board

If the common users have chaos between PC components, it's for sure the main-board. About twenty different chipsets are currently available and when we add some tenths manufacturers, we can easily achieve number 100.
The function of motherboard is to support CPU and to connect it with the other components. It contains some slots, where the cards are put. AGP supports modern graphic accelerators, PCI sound cards, internal modems, older graphic cards. IDE slot is now not actual. Also BIOS and CMOS clock are arranged there.
The motherboards differ in the speed of SYSTEM BUS. It determines the speed of giving and receiving data from and to CPU (the best ones 400 MHz). The size of main-board is important. You will not implement old AT board into ATX case.
Some boards have also sound card included.

If you don' t want to hear 4-channel sound, it' s OK.





Put some facts together:

Two motherboards from different producers, which have the same chipset,
will have nearly identical performance.
Manufacturers differ in support, reliability and compatibility of their products.
More expensive motherboards are mainly better, but not so great as they cost.
Commonly, we can consider ABIT & ASUS as the high class, MSI, GIGABYTE, AOPEN, SOLTEC as the mid-class and the other ones as low-end.



5.Hard-disk

Information on this kind of memory storer will not get lost when you switch your PC off. When you turn it again on, you will find an operating system, or programs on it again. The most important parameter is the capacity of hard-disk. The higher capacity it has, higher amount of data you can save. Any user should not buy HDD with less than 20 Gigabytes.



Hard-drive contains from two to eight inflexible platters coated with material that allows the magnetic recording of computer data. A typical hard disk rotates at 5,400/ 7,200 revolutions per minute, and the read/write heads ride over the surface of the disk on a cushion of air 10 to 25 millionths of an inch deep. A hard disk is sealed to prevent contaminants from interfering with the close head-to-disk tolerances. Hard disks provide faster access to data than floppy disks and are capable of storing much more information. Because platters are rigid, they can be stacked so that one hard-disk drive can access more than one platter.

Top products are from MAXTOR, SEAGATE, or WESTERN-DIGITAL.
Now only IDE disks are sold. The best choice of speed should be 7,200 rpm.



6. CD/RW/DVD

CD-ROM drive is a device, which can read compact discs. It can work at different speeds. CDRW (compact disc rewriter) is similar to CD-ROM drive, but it can also record data on CD medium.
DVD-ROM (digital versatile disc reader) is a device used to read DVD mediums. The DVD has advantage of capacity (at least 4.7 GB) so it is much better than CD (its capacity is 650/700 MB). In addition it can read also compact discs.

In contemporary time I do not recommend to buy an ordinary CD-ROM, because it has low usage value. If you spend a little more money you can have DVD-ROM, which can be used in much more cases.
Between models, which are already available are not big differences in speed of reading. The usual speed of CD-ROM is about 50x. The best known trade marks are Pioneer, Teac and Acer.



7. Graphic cards

They are used in computers to process data, which have to be displayed on monitor in that way that user can see it. If the memory is higher it can display more colours. If you want to use your PC for homework you need the graphic card with only 2-4 MB, but for playing games you may need 32 MB. The contemporary situation is clear: graphic cards with chips from NVIDIA dominate. The great solution is to buy one kind of GEFORCE 2- MX200 for less pretentious, GTS for higher recommendations.

Roughly, it does not matter, which manufacturer will you select.
If you want to use 2 monitors, you can choose MATROX with a function DUAL-HEAD. But these cards are not so good at 3D.



8. Sound on PC

If you think, that NVIDIA is the most powerful segment between graphic accelerators, you will not get confused if you notice that CREATIVE dominates even more between sound cards. From those times, when we were using PC-speakers flew more than 10 years. CREATIVE company makes the best products from that time. Sound Blaster Live! is still sufficient enough and it is cheaper and cheaper. But an ordinary home-user will be satisfied with any card for 500 Sk.
The price of 2 ordinary speakers also varies about 500 Sk. More expensive 4 speakers + 1 subwoofer provides the best surround experience. 9. The Case

The whole computer has to be stored in some case. It is not the only one function to store the components, but it also provides the connection between particles, it regulates the flow of air...
The most common and practical too, are MINI and MIDI TOWERS. There is enough space for 2 floppies, CD-ROM, DVD ROM and CD REWRITER, too.
Bigger towers have more space inside, what fits to greater systems, or to those who want to experiment. Higher amount of air cool CPU down better, what makes PC more stable.
The supply of energy is important. Todays' systems may need 250/300 W. We hope that this guide will help you and you will not need to do this:.

Zdroje:

MS- Encarta -
PC World 12/2001 - magazine -