tecknology and programing

A. Understanding Of RAM.
RAM (Random Access Memory) is a computer hardware that is responsible for storing data. RAM is temporary means that the stored data can be erased. Unlike the case with the ROM, ROM has the same task with the RAM but ROM is permanent in the sense that stored data can not remove. RAM is a type of memory that it can change, change as long as the computer has a life and can remember the nature of data or programs as long an electrical current and can store and retrieve data very quickly.
B. Types of RAM:
1. RAM
Was first discovered by Robert Dennard, in large-scale production in 1968, and this is where the history of ram begins. RAM requires a voltage of 5.0 volts to run at a frequency 4,77MHz, with memory access time (access time) of about 200ns (1ns = 10-9 seconds). This first-generation RAM uses 30 pin slot on the motherboard.

2. DRAM
IBM created a memory in DRAM named in 1970, its own DRAM stands for Dynamic Random Access Memory, DRAM has a working frequency varies, between 4,77MHz up to 40MHz.

3. FPM DRAM
This type of memory works like an index or table of contents. Meaning page itself is part of the memory contained on a row address. When the system requires the contents of a memory address, FPM simply take information about them based on an index that has been owned. FPM allows faster data transfer on the line (row) of the same from the previous memory types. FPM works in the frequency range of 16MHz to 66MHz with an access time of about 50ns. In addition FPM is able to process data transfer (bandwidth) of 188.71 Mega Bytes (MB) per second. FP RAM was discovered around 1987. Memory is used by the system based on the Intel 286, 386 and 486 bit.

4. EDO DRAM EDO
DRAM (Extended Data output dynamic random access memory) Memory was created in 1995. This is an improvement of FPM, EDO can shorten its read cycle so as to improve its performance by about 20 percent. EDO has access time that is quite varied, which is about 70ns to 50ns and works at a frequency of 33MHz to 75MHz. Although EDO is a refinement of the FPM, but both can not be installed simultaneously, because of differences in ability. Intel 486-compatible as well as early-generation Pentium is a database system that uses EDO DRAM. Slots used on the motherboard has 72 pins.

5. SDRAM
Kingston SDRAM created at the turn of the year 1996-1997, the module can work at the speed (frequency) the same bus / sync with the frequency that works on the processor. SDRAM is then known as PC66 because it works at a frequency of 66MHz bus. Unlike the previous memory types that require a fairly high working voltage, SDRAM only requires a voltage of 3.3 volts and has an access time of 10ns.Selang within a year after PC66 mass produced and used, Intel made the new standard type of memory which is the development of PC66 memory. By using the working voltage of 3.3 volts, have PC100 memory access time of 8ns, shorter than PC66. In addition PC100 memory can stream data at 800MB per detiknya.Selain PC800 RDRAM memory developed in 1999, SDRAM memory has not been abandoned, even by Viking, even more enhanced. As the name implies, the PC133 SDRAM memory working at 133MHz frequency bus with an access time of 7,5ns and can stream data at 1,06GB per second. Although it was developed to work on the PC133 bus frequency of 133MHz, and the memory is also capable of running at 100MHz bus frequency, although not as good as the capabilities of the PC100 SDRAM memory at frequencies tersebut.Perkembangan increasingly become - so after Mushkin, in 2000 successfully developed memory chips capable of working at a frequency of 150MHz bus, although in fact there has been no official standards regarding the frequency of the bus system or chipset of this magnitude. Still with a working voltage of 3.3 volts, have PC150 memory access time for 7NS and can stream data at 1,28GB per second. This memory is intentionally created for the purposes of overclockers, but users gaming applications and 3D graphics, desktop publishing, and server computers can take advantage of the presence of PC150 memory. Slots used on the motherboard has 168 pins.

6. DR RAM
In 1999, Rambus memory system to create a new architecture and a revolutionary, totally different from SDRAM.Oleh Rambus memory architecture, this memory is called Direct Rambus Dynamic Random Access Memory. By simply using a voltage of 2.5 volts, RDRAM working on 800MHz system bus via a bus system called Direct Rambus Channel, able to stream data at 1,6GB per second! Still in the same year, Rambus has also developed an other memory types with the same ability to DRDRAM. The difference lies only in the necessary working voltage. If DRDRAM require a voltage of 2.5 volts, the PC800 RDRAM work at a voltage of 3.3 volts.

7. DDR SDRAM
In 2000, successfully developed the ability Crucial SDRAM memory to 2-fold. The technique used is to use fully the wave frequency. If the ordinary SDRAM only perform the instructions on the positive wave, then DDR SDRAM running instruction both on the wave of positive and negative waves. Therefore, the memory of it is called DDR SDRAM stands for Double Data Rate Synchronous Dynamic Random Access Memory. With DDR SDRAM memory, system bus with a frequency of 100-133 MHz will work effectively at a frequency of 200-266 MHz. DDR SDRAM first used in ultra-speed AGP graphics card. While use of the processor, AMD ThunderBird was the first to use it. Slots used on the motherboard has 184 pins.

8. DDR3 SDRAM
The DDR3 RAM has a power requirement is reduced by about 16% compared to DDR2. It is because DDR3 is already using 90 nm technology so that the power required konsusmsi only 1.5v, much less when compared to DDR2 and DDR 2.5V 1.8v. In theory, the speed of which is owned by RAM is indeed quite stunning. He is able to transfer data at an effective clock of 800-1600 MHz. DDR3 has an internal clock 400-800 MHz, much higher than DDR2 and DDR 200- 533 at 100-300 MHz. Prototypes of DDR3 which has 240 pins. This has actually been introduced a long time ago at the beginning of 2005. However, the product itself actually emerged in mid-2007 in conjunction with a motherboard that uses the Intel P35 Bearlake chipset and motherboard that supports DDR3 slot. Slots used on the motherboard has the same number of pins with the slots DDR2 SDRAM, but notchnya different positions so that should not be able to install the module in the slot DDR3 SDRAM DDR2. This was deliberately done because electrical modules with DDR2 DDR2 have different voltages.

9. SO-DIMM
Small Outline Dual In-Line Memory Module (SO-DIMM) is a type of memory used in notebook devices. Physical form approximately half of the large regular DDR so as to further save space which is very valuable on mobile devices such as notebooks. SO-DIMM generation developments are usually in line with the development of RAM for desktop computers. When launched in the market DDR3 SDRAM, DDR3 SO-DIMM also launched. The modules use a slot that has 204 pins. Less than DDR3 SDRAM.

C. How to Work RAM

By the time we turn on the computer, the first device to work is Processor. Processor serves as a data processor and request data from storage, the Hard Disk (HDD). It means that the data is sent from the Hard Disk after a request from the processor.

But in practice it is difficult to do because the technological differences between the Processor and Hard Disk. Processor itself is purely digital components, and will process the data very quickly (the highest bandwidth currently P4 6.4 GB / s with 800MHz FSB). While Hard Disk largely mechanical technology is certainly quite slow compared to digital (Bandwidth or Transfer Rate Serial ATA HDD range from 150 MB / s). Processor data speeds theoretically range from 46x faster than HDD. That is, if Processor awaiting supply data from the HDD will happen "Bottle-Neck" very severe.

To overcome this situation, the necessary device Main Memory (Primary Memory) or so-called RAM. RAM stands for Random Access Memory. RAM Processor serves to assist in providing data "super fast" is needed. RAM functions like such as Digital HDD, RAM because all components are already using digital technology. With RAM, the processor does not have to wait for the shipment data of HDD. DDR2 RAM currently has a bandwidth of 3.2 GB / s (PC400), so as not to disrupt the supply of the current motherboard uses Dual Channel technology which can double the bandwidth becomes 2x to enlarge to 128-bit architecture. That means, two pieces of Dual Channel DDR2 mode can supply the data to the appropriate number of Processor (3.2 GB / sx Dual Channel = 6.4 GB / s).

source by : http://andoxsz.blogspot.com/2013/06/pengertian-jenis-dan-cara-kerja-ram.html