Tipping point..

Well.. I think with my last post, you know all of what you need to know if you go out to buy different components of a computer and assemble them. So, I'll drop the main hardware stuff for now. Although, I might give reviews or discuss about something new in market.

And, it is time to start with software and comparisons and maintenance.
So, see you on the other side of this post..

MB's, GB's, TB's.. But, how many??

Storage drives are getting significantly cheaper. So cheaper, in fact that people have started buying 1 TB hard drive instead of a 750 GB one. Cheap storage space is not everything. You have to consider the speed of the system as well.
While buying an internal hard drive, people often forget that a larger hard drive means a slower system. And also, more number of hard drives mean a slower system as well.
And if disaster strikes and your hard drive crashes, you lose more amount of data than you would have, had you would have had a smaller one.

Research says that as the years have progressed, hard drives have become cheaper while their reliability has plummeted considerably, especially for larger capacity hard drives.
In daily life too, you'll see 500 GB and 1 TB ones crashing more frequently than their corresponding 320 or 750 GB ones.
So the question arises, how do we choose a good HDD with ample space. Well that's extremely simple, keeping a few points in mind.
When calculating storage space requirement, do not keep more than 35 GB reserved for your system partition containing your operating system and your basic everyday applications. Add in an appropriate size for your productivity apps like adobe suites, autodesk products, etc etc.
After that do not start counting your pictures, documents, music and videos. Remember that you can save your pictures and videos to an external hard drive or the cloud for more reliable and efficient storage. Just keep the important ones on the system itself. Plus add a couple of 100 GB if you are a gamer.
But that's it, no one needs more storage than that, and there is no need to install a hard drive that's gigantic.

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.

Compatibility of RAM with the system

The second most important thing everyone needs to keep in mind is whether the RAM he/she is going to buy will actually work with the system or will it get burned as soon as it is installed. You can be sure of the compatibility of RAM with the system by a very simple test. Just locate your motherboard manual (printed or online) and see what type and speed of RAM's are safe to use with the motherboard.
The motherboard documentation will usually include the following types of specifications:

• Memory Type: DDR3 1600/1333 MHz
• This means you can ONLY use a RAM of the type DDR3.
• This also implies that you will be safe to use RAM's with the speed of either 1600 or 1333 MHz. The rest of them might not work or might get burned in due course.

• Max Memory Size: 32 GB
• This specification specifies the maximum amount of memory you can install in your system without causing any harm to it.
• You are safe to use lesser amount of RAM than specified if you want or if you are on a tight budget, but make sure you do not exceed this limit.

You should also calculate the maximum RAM supported per slot by the motherboard by dividing the Max Memory Size by the number of sockets present on the motherboard.
For example, in a system with four RAM slots, you can install an 8 GB chip in each slot for a 32 GB motherboard.
However, in a system with eight slots, you can install 4 GB chips in each slot for a 32 GB motherboard. Using a chip with a higher memory size like 8 GB ones in this case will not be beneficial for your system.

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.

Specifications of an Optical Drive

Various types of optical drives are available in the market. These include CD readers, CD writers, DVD readers, DVD writers, DVD combos, BD readers, BD writers and BD combos.

The specifications of an Optical Drive drives to be considered are:

Supported Media Types: The optical drive must support a major part of available types of discs in the market. Examples are CD-ROM ,

DVD-R ,DVD-ROM ,CD-RW ,CD-R ,DVD-RAM ,DVD-RW ,DVD+R and DVD+RW. Note that CD drives do not support DVD's or BD's and DVD drives do not support BD's. Also, the supported media types are different for a drive's read and write capabilities.

Interface: The interface that an optical drive uses and the port that it will use to connect to the system. The interfaces have transfer speeds of their own. For example, a max. of 167 MBps for IDE, 600 MBps for SATA. But, the current technologies available for optical drives can only provide speeds that are lower than modern systems. So in case, both the ports are available in your system, the interface is not much of a specification.

Buffer Size: The optical drive buffer works in exactly the same manner as the cache of a hard drive It stores a fraction of frequently accessed data that can be accessed extremely fast. It helps the system to access data from the drive even if the processor is being utilized 100% by other processes for a fraction of a second. Usually 1 or 2 or 4 MB.

Read & Write Speeds: All optical drives have different read and write speeds and different read or write speeds for different types of media. For example, DVD drives have a speed of 16x, 20x, 24x (where x is 1.35 MBps) and CD drives have a speed of 32x, 48x, 52x (where x is 150 KBps). An optical drive will always write different types of media at different speeds (For example, a CD at 48x, a DVD at 16x and a re-writable DVD at 4x). 

Specifications of a CPU: part 2

Rest of the specifications of a CPU to be considered are:

• Instruction Set Size: Size of the instructions the processor can address simultaneously. It also defines the maximum amount of memory that the CPU can address. Currently, 32-bit and 64-bit.
• Memory Type: The standard and speed of RAM that the CPU is designed to address efficiently. If the RAM used in the system is other than the one specified by the CPU manufacturer, it may cause the system to lag.
• Max Memory Size: The maximum amount of physical memory that the CPU can support. If more RAM is installed than this, it may result in an unstable system.
• Number of Memory Channels: It specifies the number of RAM slots the CPU can work with efficiently. If the CPU is installed on a motherboard with more slots than this, it will cause the system to lag.
• PCI-E Support: Number of PCI Express slots supported and the PCI-E standard supported.
• Integrated Graphics: If the CPU has integrated graphics unit, then the graphics frequency is also to be considered.
• Socket Size: If you need to replace your processor, you need to be sure that the processor's socket size matches with the socket size of your existing motherboard.

Just keep in mind all of the above mentioned specifications while choosing a processor and you will have a super performance system.

Specifications of a CPU: part 1

The processors also have performance specifications that a buyer must know accurately before purchasing the product. As in the case of Hard Disks, better specs of the CPU will make the system perform faster. This topic has been divided into two posts to make them short and readable. The specification categories are:

• Number of Cores: Cores are the physical sub-units of a processor that can process individually. Each core has its own computing units, CPU caches and lookaside buffer. More the number of cores, more instructions can be executed independently at the same time.
• Number of Threads: Number of Threads are the hardware ability of a processor to execute that many logical processes within a single core or processor. More the number of threads, more instructions can be executes on the same processing unit.
• Clock Speed: It is the frequency at which the CPU executes the instructions. It is measured in billions of cycles per second (GHz). This determines the actual processing speed of the processor. But, having a processor clocked at 3.4 GHz isn't the sole factor to guarantee a fast computer.
• CPU cache: Integrated on the CPU die itself, the CPU cache is the fastest memory unit of the system. It is responsible to make the processing of data faster in processes where data has to be transferred between the processor and the RAM.
• DMI/FSB: Direct Media Interface or DMI is the technology that is used in Intel's i3, i5, i7 processors that has separate channel of buses for transfers to and fro. One channel each is provided for RAM, PCI-E and other devices. Front Side Bus or FSB was the technology that was used in processors prior to i3. FSB has a single channel of buses for transfers to all the components and devices of the system.

Rest of the specifications to be continued in the next post.

Hardware caches

The first type of caches, the Hardware caches are usually memory chips that have been embedded within a device. The most common Hardware caches found in a computer system are:

• CPU cache: The L1,L2,L3 caches are used to speed-up data transfer between the processor and the main memory(i.e. RAM). The L1 and L2 caches are built right into the processor chip making them extremely fast. Whereas the newer L3 cache which also has higher capacity than L1 and L2, may be built into the motherboard as well.

• Optical drive cache: A small cache (typically 1-2 MB) is provided in all optical drives, whether CD or DVD or BD. This cache is present so that the disk burner has data available for burning, even if the CPU hits 100% utilization in some other process for a fraction of a second. The cache is also used to store data for fast access when a readable disk is first inserted into the drive.

• Hard-Disk cache: Hard-disks are the fastest permanent storage devices. They can virtually read and write data at the same time. For this purpose, a cache memory is provided in the hard drives that perform in a similar manner like the optical drive caches. The only difference is in their memory size. These may range from 8MB to 64MB.

Usually, the Hard-Disk and the Optical Disk caches are built into the hard-disk controller and the optical disk controller which are present on the hard-drives and the optical drives themselves.

Cache: Types and Functions

Cache is the memory area where a part of the most frequently (more frequently than data in the RAM) is stored.

Caches were introduced to further enhance the mismatch of various hardware components of the computer like that of the processor and peripheral devices.

The purpose of caches is simple. They enhance the speed of a computer's hardware and software parts.

Cache is of two types: Hardware and Software.

The hardware caches are usually memory chips embedded within a hardware device. The most common example of this are the L1,L2 and L3 caches of modern processors.

The software caches is the ability of the software to save the most accessed user data on the Hard-Disk or the RAM. An example of this is the internet browser cache that contains cookies, form data and partial website data.

Ports for storage devices

Computer systems have a variety of secondary storage devices, some essential and the others optional. Some of these include hard-disk drives, optical drives, tape drives, floppy drives, etc.

For the transfer of data to and fro from the devices controllers are required to control the ports for connecting the devices. For the ports already present in the motherboard, usually the controller is on-board the motherboard too. The ports for hard-disk drives and optical drives include:

Parallel ATA (PATA/IDE):

• 40 pin cable and port
• max cable length: 45cm
• max number of hard drives: 4 (only in some motherboards, 2 per cable)
• max transfer speed: 133 MB/s

Serial ATA (SATA):

• 7 pin cable and port
• max cable length: 1m
• max number of hard drives: 8 (till now, one per cable)
• max transfer speed: 150-600 MB/s

SATA ports are fast replacing PATA ports. Controllers for extra ports like additional SATA or PATA ports, SCSI, USB, etc. that have been added via PCI card or similar are built on the PCI card itself.

There are ports for additional storage expansion as well like USB and SCSI. SCSI is mainly used with servers that have large arrays of hard-disk drives whereas USB controller is already present on the motherboard. The latest USB 3.0 specification is supposed to achieve 600 MB/s.

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

Motherboard : graphically revisited

In the post meant for the introduction of the Motherboard, we discussed it is called so because it is the backbone of all the components of a computer system. One of the most important point for assembling a computer is the knowledge is to know all the ports of the Motherboard.

This post is only dedicated to studying the placement of various

chips and ports present on the Motherboard with the help of good hi-def images..

In the next post, I'll write in detail about the ports of a Motherboard.