A note on Computer Hardware

Mother Board and CPU


If your computer runs slowly overall,a new processor can potentially improve the performance.The motherboard and the processor work as a team and most motherboards work with only a short list of processors.Motherboard is the big circuit board inside the case that every thing plugs into.The capabilities of the motherboard you have determine the processor you can use, the type amount of memory you can have ,the video card type and more.A computer that uses an old processor is probably an old computer with other old components.The hard disk is probably small,and the memory insufficient for today's programmes.It is cheaper to buy a whole new computer than to upgrade individual parts on it.

There are two kinds of processors you can buy: Replacement processors and Upgrade processors.Replacement processors are "regular"processors,the same type you would buy if you were creating a whole new system.Your system is a good candidate for a replacement processor if your motherboard's manual indicates that it can accept a faster processor than what you currently have."Upgrade processors"are designed to work with a variety of motherboards and to replace a variety of existing processors.These typically double or even trible the speed(in MHz)of your current system.

RAM


Lack of adequate memory is one of the most common reasons a computer runs slow.When there is not enough memory ,windows relies heavily on virtual memory which is slow and inefficient.

Memory Types:-When you want to purchase memory be sure to know what kind of memory your system needs.The memory sold these days are of two types:-SIMMs(Single Inline Memory Modules) and DIMMs(Dual Inline Memory Modules).Newer the system more likely it uses DIMMs.

SIMMs are found in 486 and some pentium systems.SIMMs come in 72-pin or 30-pin sizes,72-pin being the most common.It comes in three varieties

1) True parity memory:- This memory is for systems that require parity memory.Many older 486 systems require true parity.Look for a 36 in the specifications for parity memory.,as in 16X36-60ns.

2) Fast page mode(FPM)memory.FPM is generic memory.It works in just about any system that requires non-parity memory and doesnot mention anything about EDO.Look for a 32 in the specifications for this,as in 16X32-60ns.

3)Extended out(EDO) memory.:-This is a newer,better kind of non-parity memory.Many of the pentium class systems use it.Most of the systems currently being sold use 168-pin dual inline memory modules(DIMMs).One variety,called S-DRAM DIMM,is the latest rage because it is faster and better than SIMM.You can find DIMM in PentiumII and Pentium III systems.
YOu can buy memory modules in various denominations ranging from 256K(1/4 of MB)to 128 MB and higher.You need to make sure when choosing a denomination that your motherboard supports it and that you are not mixing denominations in a memory bank.Each DIMM slot is a bank unto itself,so you have not to worry with DIMMs;but most SIMM slots work in pairs and you must have the same denomination in each slot of pair. RAM also comes in different speeds,measured in nanoseconds(ns).A lower number is faster and faster is better.Most RAM you buy today is 60 ns,but you can buy 70 or 80 ns at a discount.

Determining the memory you need:-To determine what kind of memory to buy you need to know two things.
1)What open memory slots you have on your motherboard.

2)What type,speed,and denomination your motherboard accepts.

Hard disk


Hard disks are distinguished from one another in several ways: the interface they use,their capacity and how quickly they can read and write data.

Chosing an interface:-Your current hard disk is probably an IDE of some variety.These drives offer decent performance at a very good price,and they run on almost any computer.Your computer has built in support for four IDE devices, so you can probably add another IDE drive without buying anything extra.The most common types of IDE-compatible drives are EIDE(E stands for enhanced) and ATA-2,There is also a new IDE type,UltraDMA(UDMA)IDE which offers improved performance over other types of IDE drives.

you can also get SCSI(Small Computer Systems Interface) hard disks.These hook up to SCSI interface cards, so if you don't already have a SCSI interface card in your system,you need to buy one if you want to use a SCSI hard disk.SCSI hard disks are usually more expensive than IDE drives and are considered superior.

When chosing a new hard disk capacity always overestimate.you can buy anything from 1.2 GB to 100 G.B or more.In additiontn to capacity you also need to consider the physical size of the drive to fit in the space available in your computer.

Hard disks have two critical measurements.

1) Average access time:-It is the time it takes for the drive head to reach and read the average bit of data.It is measured in milliseconds(ms).The lower the number the faster the drive.A decent speed is 10ms.

2)Data transfer rate:- This measurement refers to how quickly data moves from the hard disk to memory.The higher the number the fater the rate.Look for adata transfer rate of 11 to 16 megabytes per second.Popular brands in hard disk include Maxtor,Western,Digital,Seagate,Quantum,and JTS.

Repartitioning the hard disk:-this is not necessary to correct system problems.The only reason to repartitionthe hard disk is to allocate the space on the hard disk in a different way.

Reformatting:-If you repartition,you also need to reformat.If you don't repartition,reformatting is optional.Formatting adrive wipes every thing from it:programmes,data,system files,startup files and so on.It provides a truely clean slate on which to reinstall,guaranteeing that the files that were causing the problem are eradicated.Reformatting is suggested in the following cases.



If you are running low on hard disk space following methods of streamlining will help.


(Remember not to delete files with the following extensions)
You can safely delete files with following extensions..

Monitor


Screen size:-This refers to the diameter of the screen which range from 14 inches to 21 inches.When you see the listed size you may see two sizes like 17-inch(15.9-inch viewable);so while comparing the sizes of two monitors,compare the viewable size of the two,which really matters.

Maximum Resolution:-A monitor's maximum resolution refers to the maximum number of seperate dots it can display horizontally and vertically.Many small monitors can display up to 1024X768---that is 1024 dots across and 768 dots down.Larger monitors display much higher resolutions;the better quality the monitor,the higher its maximum resolution

Monitor Technology:-

Your video display is made up of tiny dots.The dot pitch is the measurementof how close together the dots lie.A dot pitch of .28 is considered the min.adequate amount.Lower dot pitch is better.Higher dot pitch makes the picture less crisp.

The most common kind of monitor is called dot trio shadow mask.These monitors deliver clean edges and sharp diagonals which is important for showing text on screen.

Another kind of monitor has an aperture grille rather than dots.Their performance is measured in stripe pitch rather than dot pitch.Look for a stripe pitch of .25 or less.These monitors have superior brightness and contrast,but their poorer diagonals make them less well suited for diplaying text.

A third kind of monitor is a slot mask>It combines the attributes of a shadow mask and a aperture grille.It uses a .25mm mask with eleptically shaped phosphors.

The final kind of monitors,LCD, is mostly found on laptop computers..Some manufacturers are beginning to use LCD in large desktop monitors with stunning results.These monitors can be nearly flat and the displays are beautiful.

Interlacing and Refresh rate.To understand these factors we need to know abit about how monitors work.The screen is made up of tiny dots that contain particles that glow when alight hits them.A light gun(or a set of three guns:blue,red and green) moves very quickly over the monitor,dot by dot,making each dot glow with the appropriate color.Without being refreshed by the ligght gun,the particles in each dot fade quickly,so the light gun must refresh each particle hundreds of times per second.The rate at whichthe particles are refreshed with the light gun is the refresh rate.Some times the display appears flickering as a result of low refresh rate.

On some cheaper monitors ,the light gun simply cannot keep up;to compensate,the manufacturers use a scheme caled interlacingto keep the display readable.With interlacing,the light gun scans alternate horizontal lines, rather than every line, on each pass, so the gun can make twice the no. of passes in a given amount of time.Because the horizontal lines are so close together our eye cannot pick up that evry alternate line is not refreshed.

The best monitors are ones capable of non-interlaced operation and a high refresh rate.Look for a monitor with a maximum refresh rate of atleast 85KHz.

Other Monitor Features.:-Here are some extras which are oprional in a monitor.but are nice.