DDR3 SDRAM

DDR3 SDRAM

In electronic engineering, DDR3 SDRAM or double-data-rate three synchronous dynamic random access memory is a random access memory interface technology used for high bandwidth storage of the working data of a computer or other digital electronic devices. DDR3 is part of the SDRAM family of technologies and is one of the many DRAM (dynamic random access memory) implementations.

DDR3 SDRAM is an improvement over its predecessor, DDR2 SDRAM, and the two are not compatible. The primary benefit of DDR3 is the ability to transfer at twice the data rate of DDR2 (I/O at 8× the data rate of the memory cells it contains), thus enabling higher bus rates and higher peak rates than earlier memory technologies. There is no corresponding reduction in latency, as that is a feature of the DRAM array and not the interface. In addition, the DDR3 standard allows for chip capacities of 512 megabits to 8 gigabits, effectively enabling a maximum memory module size of 16 gigabytes.

With data being transferred 64 bits at a time per memory module, DDR3 SDRAM gives a transfer rate of (memory clock rate) × 4 (for bus clock multiplier) × 2 (for data rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus with a memory clock frequency of 100 MHz, DDR3 SDRAM gives a maximum transfer rate of 6400 MB/s.

DDR3 SDRAM

DDR2 SDRAM

DDR2 SDRAM

DDR2 SDRAM is a double data rate synchronous dynamic random access memory interface. It supersedes the original DDR SDRAM specification and the two are not compatible. In addition to double pumping the data bus as in DDR SDRAM, (transferring data on the rising and falling edges of the bus clock signal), DDR2 employs an I/O buffer between the memory and the data bus so that the data bus can be run at twice the speed of the memory clock. The two factors combine to achieve a total of 4 data transfers per memory clock cycle.

With data being transferred 64 bits at a time, DDR2 SDRAM gives a transfer rate of (memory clock rate) × 2 (for bus clock multiplier) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus with a memory clock frequency of 100 MHz, DDR2 SDRAM gives a maximum transfer rate of 3200 MB/s.

DDR2-SD RAM

RDRAM

RDRAM

RDRAM is a wide-channel device. They transfer data only 16 bits (2 bytes) at a time (plus 2 optional parity bits), but at much faster speeds. RIMM typically runs at 800MHz, so the overall throughput is 800 × 2, or 1.6GB per second for a single channel—the same as PC1600 DDR SDRAM. Dual-channel PC800 RDRAM is also currently the fastest type of PC memory, followed by PC2100 DDR SDRAM. Whether your board supports (requires) dual-channel RDRAM is dictated by the motherboard chipset; currently, the Intel 840 and 850 chipsets support dual-channel RDRAM.

A Typical RD RAM (RDRAM)

SDRAM

SDRAM

 Synchronous DRAM (SDRAM) is for Synchronous DRAM, a type of DRAM that runs in synchronization with the memory bus. SDRAM delivers information in very high-speed bursts using a high-speed, clocked interface

RAM: Random Access Memory

RAM: Random Access Memory

RAM (random access memory) is what is most often referred to when PC memory is discussed. RAM is the form of volatile memory used to hold temporary instructions and data for manipulation while the system is running.

Nonvolatile and Volatile Memory

Nonvolatile and Volatile Memory

There are two major classes of computer memory: Nonvolatile and Volatile. Nonvolatile Memory is retained even if the power is shut off. The setup data held in CMOS, discussed in the preceding lessons, is a good example of nonvolatile memory. If the data is lost when the computer loses power, the memory is said to be Volatile.

Memory

Memory

All computer memory is used to hold binary strings of data destined to be manipulated by the CPU. Think of memory as a vast bank of switches with two positions: on or off. Off is given the value of "0"; on is given the value of "1." This allows the switches to hold binary data based on whether they are open or closed.

Memory Unit (MU)

Memory Unit:-

Memory unit that is also called Main Memory or Random Access Memory is the Primary Unit of the computer. The computer cannot start without Main memory. Main memory is directly accessible by CPU of the computer. The data is stored in main Memory before and after processing. It is a volatile Memory it means it only stores data when computer is turned on.

When we start a computer data from Hard disk is loaded in RAM. The most part of RAM is used by Operating System of the Computer. Remaining Main Memory is distributed between application software.

The Capacity of main memory is measured in Bytes. RAMs are available in GB (Gigabytes).