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.

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.

Specifications of a Hard Disk

Hard Disks have a few performance specifications that a buyer must always know accurately before purchasing the hard disk. Better specs will obviously make the system perform faster. The specifications are:

• Capacity: The amount of data that the disk can store. Usually 100's of GB's or TB's.
• Cache: A small memory chip that stores a fraction of frequently accessed data that can be accessed extremely fast. Usually 8 or 16 or 32 or 64 MB.
• Spin Speed: The speed at which the hard disk platter rotates. Usually, 5400 or 7200 or 10000 rpm.
• Average Seek Time: The average time in which the R/W head can be positioned over the requested track for random read/write requests. Usually, ~8-10 ms.
• Average Latency: The average time for the disk to rotate the platter and position the correct sector under the R/W head. Usually, ~3-5 ms.
• Interface: The interface that the hard disk uses and the port that it will use to connect to the system. The interfaces also have transfer speeds of their own. For example, a max. of 167 MBps for IDE, 600 MBps for SATA.

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.

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