* Definition of -RAM (random access memory) :- -RAM is the place in a computer where the operating system, application programs & data in current use are kept so that they can be quickly reached by the computer's processor. -RAM is much faster to read from and write to than the other kinds of storage in a computer, the hard disk, floppy disk, and CD- ROM.

-* Cont. : -Additional RAM allows a computer to work with more information at the same time which can have a dramatic effect on total system performance. -RAM is also known as main memory, internal memory, primary storage, memory “stick” & RAM “stick”.

-* Cont. : -RAM come with various storage capabilities. -RAM memory modules can be purchased in 256MB, 512GB, 1GB, 2GB & 4GB sizes.

-* Cont. : -However, the data in RAM stays there only as long as your computer is running. -When you turn the computer off, RAM loses its data, When you turn your computer on again, your operating system and other files are once again loaded into RAM, usually from your hard disk.

*How Big is RAM ?! -RAM is small, both in physical size it's stored in microchips & in the amount of data it can hold. It's much smaller than your hard disk. -A typical computer may come with 256 million bytes of RAM and a hard disk that can hold 40 billion bytes.

*Cont. :- -RAM comes in the form of microchips & also in the form of modules that plug into holes in the computer's motherboard. -These holes connect through a bus or set of electrical paths to the processor. -The hard drive, on the other hand, stores data on a magnetized surface that looks like a phonograph record.

* Cont. :- -Most personal computers are designed to allow you to add additional RAM modules up to a certain limit. -Having more RAM in your computer reduces the number of times that the computer processor has to read data in from your hard disk, an operation that takes much longer than reading data from RAM.

* Type of RAM :- 1- SIMM 2- FPM RAM 3- EDO RAM 4- SDRAM 5- DDR RAM 6- DDR2 RAM 7- DDR3 RAM 8- RD-RAM 9- SODIMM

* 1- SIMM :- -Which stands for [Single In-Line Memory Module]. -This memory board used a 30-Pin connector & was about 3.5 x.75 inches in size (about 9 x 2 cm).

* Cont. :- -In most computers, we had to install SIMMs in pairs of equal capacity & speed, This is because the width of the bus is more than a single SIMM. -For example, we would install two 8MB SIMM to get 16MB total RAM.

* Cont. :- -Each SIMM could send 8 bits of data at one time, while the system bus could handle 16 bits at a time. -Later SIMM boards, slightly larger at 4.25 x 1 inch (about 11 x 2.5 cm), used a 72 Pin connector for increased bandwidth & allowed for up to 256MB of RAM.

* 2- FPM RAM :- -FPM DRAM Stand for [Fast Page Mode Dynamic Random Access Memory]. -It is was the original form of DRAM. -It waits through the entire process of locating a bit of data by column and row & then reading the bit before it starts on the next bit.

* Cont. :- -Maximum transfer rate to L2 cache is approximately 176MBps.

* 3- EDO RAM :- -EDO DRAM Stand for [Extended Data-Out Dynamic random access Memory]. -It’s doesn’t wait for all of the processing of the first bit before continuing to the next one.

* Cont. :- -As soon as the address of the first bits is located, EDO DRAM begins looking for the next bit. -It is about five percent faster than FPM. -Maximum transfer rate to L2 cache is approximately 264MBps.

* 4- SDRAM :- -Which is short for [Synchronous Dynamic Random access memory]. -The idea of this type is that most of the time the data needed by the CPU will be in sequence.

* Cont. :- -It is the most common form in desktops today. -Maximum transfer rate to L2 cache is approximately 528MBps.

* 5- DDR RAM :- -Which stands for [Double Data Rate], which is a type of SDRAM & appeared first on the market around The difference between SDRAM & DDR RAM is that instead of doubling the clock rate it transfer data twice per clock cycle which effectively doubles the data rate.

* Cont. :- -DDR RAM has become mainstream in the graphics card market & has become the memory standard.

* 6- DDR3 RAM :- -Which stands for [Double Data Rate 2] is a 2 nd newer version of DDR which is twice as fast as the original DDR RAM. -DDR2 RAM came out in mid 2003 & the first chipsets that supported DDR2 came out in mid 2004.

* 7- DDR3 RAM :- -It is run at higher clock speeds as mentioned, this is mean that all components within the Graphics Card can benefit from receiving information at a faster rate. -Pixel Shader Units & Vertex Shader units can receive the information faster & therefore work more efficiently, giving a boost to frame rates while gaming.

* Cont. :- -So it give more support in gaming PC. -The data speed of DDR3 RAM is Faster than DDR2 RAM.

* 8- RD-RAM :- -Short for RAMBUS DRAM, whereas the fastest current memory technologies used by PCs (SDRAM) can deliver data at a maximum speed of about 100 MHz, RDRAM transfers data at up to 800 MHz. -In 1997, Intel announced that it would license the RAMBUS technology for use on its future motherboards.

* Cont. :- -Though some motherboards can use RDRAM as system memory, it is so fast, most boards cannot fully benefit from the speed. -Because of this, RDRAM is typically used for video memory on graphics accelerator cards, for cache memory (located on the CPU), & for system memory in high- performance workstations & servers.

* 9- SODIMM :- -Many brands of notebook computer use proprietary memory modules, but several manufacturers use RAM based on the [Small Outline Dual Inline Memory Module] (SODIMM) configuration. -SODIMM cards are small, about 2 x 1 inch & have 144 or 200 pins, Capacity range from 16MB to 1GB per module.

* Cont. :- -To conserve space, the Apple iMac desktop computer uses SODIMM instead of the traditional DIMMs. -Sub notebook computers use even smaller DIMMs, known as MicroDIMMs, which have either 144 pins or 172 pins.

* Reference : specifications/ Thanks For your Listening =)