SO-DIMM

An SO-DIMM, or small outline dual in-line memory module, is a type of computer memory built using integrated circuits.

SO-DIMMs (also written SODIMMs) are a smaller alternative to a DIMM, being roughly half the size of regular DIMMs. SO-DIMMs are often used in systems that have limited space, such as notebooks, small footprint PCs (such as those with a Mini-ITX motherboard), high-end upgradable office printers, and networking hardware like routers.

PC6400 DDR2 SO-DIMM (200 pins)

PC3-10600 DDR3 SO-DIMM (204 pins)

Visual identification

  Most types of SO-DIMMs can be recognized at a glance by the distinctive notches that “key” them for different applications :

SDRAM (synchronous DRAM)

 

SDRAM (synchronous DRAM) is a generic name for various kinds of dynamic random access memory (DRAM) that are synchronized with the clock speed that the microprocessor is optimized for. This tends to increase the number of instructions that the processor can perform in a given time. The speed of SDRAM is rated in MHz rather than in nanoseconds (ns). This makes it easier to compare the bus speed and the RAM chip speed. You can convert the RAM clock speed to nanoseconds by dividing the chip speed into 1 billion ns (which is one second). For example, an 83 MHz RAM would be equivalent to 12 ns.

Source : http://whatis.techtarget.com

DRAM (Dynamic Random Access Memory)

 Dynamic random access memory (DRAM) is the most common kind of random access memory (RAM) for personal computers and workstations. The network of electrically-charged points in which a computer stores quickly accessible data in the form of 0s and 1s is called memory. Random access means that the PC processor can access any part of the memory directly rather than having to proceed sequentially from some starting place. DRAM is dynamic in that, unlike static RAM (SRAM), it needs to have its storage cells refreshed or given a new electronic charge every few milliseconds. Static RAM does not need refreshing because it operates on the principle of moving current that is switched in one of two directions rather than a storage cell that holds a charge in place. Static RAM is generally used for cache memory, which can be accessed more quickly than DRAM.

DRAM stores each bit in a storage cell consisting of a capacitor and a transistor. Capacitors tend to lose their charge rather quickly; thus, the need for recharging. A variety of other RAM interfaces to the computer exist. These include: EDO RAM and SDRAM.

Source : http://searchstorage.techtarget.com

RAM - Random Access Memory

Types of RAM

There are two different types of RAM:

• DRAM (Dynamic Random Access Memory)
• SRAM (Static Random Access Memory).

The two types of RAM differ in the technology they use to hold data, with DRAM being the more common type. In terms of speed, SRAM is faster. DRAM needs to be refreshed thousands of times per second while SRAM does not need to be refreshed, which is what makes it faster than DRAM.

DRAM supports access times of about 60 nanoseconds, SRAM can give access times as low as 10 nanoseconds. Despite SRAM being faster, it's not as commonly used as DRAM because it's so much more expensive. Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.

SSD

Short for Solid-State Drive or Solid-State Disk, SSD is a drive that uses non-volatile memory as a means of storing and accessing data, much like computer RAM. Unlike other storage devices such as hard drives, an SSD has no moving parts, which gives it advantages such as accessing stored information faster, produces no noise, often more reliable, and consume much less power than the traditional hard drive (HDD) found in computers. In the picture to the right, is a Crucial SSD and an example of what a SSD looks like. 

The first SSD was implemented in IBM supercomputers in the 1970s and 1980s. They have since been drastically improved upon and offer storage capacities of 128GB and 256GB for home computers. Unfortunately, because of the much greater cost per GB of storing information these drives have not yet become suitable solutions for replacing a standard computer's hard drive. However, are a great solution for netbooks, nettops, and other applications that don't require several hundred GB of space. These drives are also popular for computer enthusiasts who use the smaller SSD to run only Windows and some of their more popular programs and then have all their data files such as pictures and music files on a second larger traditional hard disk drive (HDD).

Tip: A SSD may also be referred to as a flash drive, which should not be confused with a USB jump drive or Adobe Flash.

source : http://www.computerhope.com

Know Your Hard Drive

Alternatively referred to as a hard disk drive and abbreviated as HD or HDD, the hard drive is the computer's main storage media device that permanently stores all data on the computer. The hard drive was first introduced on September 13, 1956 and consists of one or more hard drive platters inside of air sealed casing. Most computer hard drives are in an internal drive bay at the front of the computer and connect to the motherboard using either ATA, SCSI, or a SATA cable and power cable. Below, is a picture of what the inside of a hard drive looks like for a desktop and laptop hard drive.

Know the functions of the computer motherboard

Motherboard is the central component of the controller that regulates the work of all the components mounted on it. Regulate the provision of electrical power to each component. Data traffic are all regulated by the motherboard, starting from the storage device (hard drive, CD-ROM), a data input device (keyboard, mouse, scanner), or a printer to print.