Buying a powerful Power Supply

Since the PSU's or the Power Supply Units supply power to all of the components of the computer. It is extremely essential that one buys a PSU that provides enough power so as to provide enough power to the components that they do not slow down because of lack of power.
But buying a huge power supply does not mean buying a 2000 Watt SMPS. Doing that will take your electricity bill up to twice the normal. You need to buy a power supply that has a good amount of power while not having an excess of it.
Well, for starters you can be safe with a power supply of 300 Watts to the motherboard, a 20 Watt supply per drive, and a 20 Watt supply per 1 GB of RAM. That all works if you have a really low-end graphics card that doesn't require any more than 150 Watts to run and does not require any special connector to be powered.

• But in case your system has a high-end GPU, you'll have to add the required power of the GPU to  the above wattage and then buy the PSU. Also don't forget to check if the GPU requires an extra cable for power. If yes, add it to the required specifications for the PSU.
• Next, look for a power supply unit having a good amount of connectors of all types i.e. SATA, molex and PCI-E. Its always beneficial to buy one that has one or two connectors of SATA and molex for future expansions.
• And obviously, the PSU you are buying should have a large 60 mm fan, if not 120 mm one for excellent cooling performance for your system. My recommendation: Buy one with 120 mm fan even if it costs an additional $10.

Non-Compatibility of Processor and Motherboard

Processor and Motherboard compatibility is the most important thing to know before you go about assembling a computer. The reason being if you buy a processor that does not support your motherboard or vice-versa, you'll end up losing a huge amount of money because the processor and the motherboard combo are the most expensive components apart from the graphic card.
In case your processor and motherboard are not compatible with each other, either of the following scenarios may take place.

• First, your new processor might not fit into the socket of the motherboard. This option is the better of the two, because it will not damage any component of your system. The only solution is to buy either a new processor or a new motherboard.
• Second, and you better hope this does not happen. The second case, which rarely happens is the time when your incompatible processor gets seated firmly in the motherboard but, does not get recognized by the motherboard and/or perform normally. This may damage either/or both of the components.

So it is extremely necessary that you know if the processor and the motherboard are compatible with each other or not before you go shopping.

How to choose the right cabinet for your desktop?

 The first and foremost important thing to consider before looking for a desktop case is that you know the form factor of your motherboard. If you know it, very well. However, if you don't know it, you should refer to the specifications of your motherboard or check it online. It is usually of the form ATX or micro ATX or BTX or micro BTX. This is important because the form factor decides the shape and size of the motherboard and we would obviously like to buy a cabinet, that can house our motherboard.

Secondly, it is a must that you buy a cabinet that has ample space inside. In simple words, buy a large cabinet. It promotes air flow and will keep your system cool. Thirdly, the case should not conduct electricity. Ensure that the case is not metallic and that each and every screw-hold for the components has rubber or plastic insides. This will help in preventing your system components from getting an electric shock.

Fourthly, there must be ample additional cooling fan attachment space in the cabinet. This is the first and the most critical point for gaming systems. Apart from the mandatory cooling fans present in your SMPS, over the CPU, and above the GPU, there should be provisions to attach more fans at the rear, the left side and in hardcore systems, the front as well.

Fifthly, see that the case has ample of hard drive and optical drive bays, so that you can attach as many HDD's and ODD's as you want. And optionally, look out for the optional components like headphone jacks, the number of USB connectors, etc. that help you in being more productive.

The image on the left shows a nice cabinet, with good cooling provisions.

Graphic Cards: model numbers

Writing this post in response to the guy who called me up yesterday night inquiring about two graphic cards (GPU's) and among the two is better. The GPU has specifications that need to be compared to decide which among the available ones is the best. However, there is a short-cut that can roughly point you to the right card. This post explains about that short-cut. As you might already know, there are 2 big players in the GPU market, nVidia and ATI. Let me start with the help of an example from both.
Firstly let us pick a GPU, let's say nVidia GeForce GTX 580. The model number 580 has three digits:

• 5 - It represents the family of the GPU. The higher the number, the latest technology it uses and that it can support.
• 8 - It represents the performance of the card. The higher the number, the better and faster it can compute.
• 0 - It represents trade-off between graphics quality and performance speed. The higher the number, the higher the clock speed but lesser quality.

Now let us pick an ATI Radeon HD 6870 GPU. The model number 6870 has four digits out of which the last digit is insignificant:

• 6 - Same as in nVidia, it represents the family of the GPU. The higher the number, the latest technology it uses and that it can support.
• 8 - It represents the performance of the card. The higher the number, the better and faster it can compute.
• 7 - It represents the stability and reliability of the card. The higher the number, more stable it is.

Obviously, the lowest model number would cost the least. But, since we do not want outdated technology, it is necessary to buy the right Graphic Card out of our available budget. Choose a higher performance graphic card if you want to play the latest games flawlessly, but choose a newer graphic card if you want to extend the life of your PC. Sometimes, u might face a dilemma when you go GPU-shopping. For example, you might find the price of nVidia Geforce GTX 480 and GTX 550 almost similar. The choice is yours, but remember the points mentioned above and you will add a gem to your system.

PCI-Express: why it is better

PCI Express or PCIe is an expansion card standard that was designed to replace the older AGP, PCI and PCIx bus standards. The PCI-Express standard offers higher system bus throughput and has lower I/O pin count.

PCIe has serial links between devices called Lanes, unlike the parallel connections present in PCI buses. PCIe can be a x1, x4, x8 or x16 type where the number equals the number of lanes. ( D,E : ports and sockets of a motherboard )

The PCIe (common revision 2.1) has a bandwidth of 16 Gbps for a 16 lane link (x16).

PCIe slot can be used for placing expansion port card, modems or sound cards, etc. But, Graphics performance can benefit the most with the use of PCIe because they require the maximum bandwidth for transfers. So, the graphic cards (or GPU) are built for and placed in PCIe slots.

Motherboard: ports and sockets

This image shows only those interfaces (ports and sockets) that are important to our interest and point of view.

The rest of the small semiconductor parts of the motherboard are not of our interest, but for their designer.

In this post, only the names of all the interfaces have been mentioned.

Other than these interfaces, there are numerous chips and IC's for various functions as well.

They along with the functions of these interfaces would be described sometime later.

The components are so named:

A,B : PCI connector

C : CMOS battery

D : PCI-E (x1) connector

E : PCI-E (x16) connector

F : S/PDIF connector

G : Back-panel for I/O devices

H : 12V processor power (4-pin)

I : Rear chassis fan header (3-pin)

J : Processor socket

K : Processor fan header (4-pin)

L,M : RAM (channel A,B) sockets

N : Chassis intrusion header

O : Serial port header

P : Floppy Drive connector

Q : Main power connector (24-pin)

R : Parallel ATA (IDE) connector

S : Serial ATA (SATA) connectors

T : Front panel header

U : Alternate front panel power LED header

V : BIOS configuration jumper

W : Front USB headers

X : Speaker

Y : Front chassis fan header (3-pin)

Z : Front panel audio header