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DDR-2

"Double Data Rate 2." DDR2 RAM is an improved version of DDR memory that is faster and more efficient. Like standard DDR memory, DDR2 memory can send data on both the rising and falling edges of the processor's clock cycles. This nearly doubles the amount of work the RAM can do in a given amount of time. DDR and DDR2 are also both types of SDRAM, which allows them to run faster than conventional memory.

DDR

"Double Data Rate." It is an advanced version of SDRAM, a type of computer memory. DDR-SDRAM, sometimes called "SDRAM II," can transfer data twice as fast as regular SDRAM chips. This is because DDR memory can send and receive signals twice per clock cycle. The efficient operation of DDR-SDRAM makes the memory great for notebook computers since it uses up less power.

Memory Bank

A memory bank is a designated section of computer memory used for storing data. Much like financial bank, a memory bank serves as a repository for data, allowing data to be easily entered and retrieved. Banks are organized into logical units that are ordered consecutively, providing easy to access individual items.

Virtual Memory

Because your computer has a finite amount of RAM, it is possible to run out of memory when too many programs are running at one time. This is where virtual memory comes in. Virtual memory increases the available memory your computer has by enlarging the "address space," or places in memory where data can be stored. It does this by using hard disk space for additional memory allocation. However, since the hard drive is much slower than the RAM, data stored in virtual memory must be mapped back to real memory in order to be used.

DDR-3

Double Data Rate Type 3." DDR3 is a type of SDRAM that is used for system memory. It is available in both DIMM and SO-DIMM form factors. DDR3 RAM is similar to DDR2 RAM, but uses roughly 30% less power and can transfer data twice as fast. While DDR2 memory can transfer data at up to 3200 MBps (megabytes per second), DDR3 memory supports maximum data transfer rates of 6400 MBps. This means computers with DDR3 memory can transfer data to and from the CPU much faster than systems with DDR2 RAM. The faster memory speed prevents bottlenecks, especially when processing large amounts of data. Therefore, if two computers have the same processor clock speed, but different types of memory, the computer with DDR3 memory may perform faster than the computer with DDR2 memory.

ECC

Error Correction Code." ECC is used to verify data transmissions by locating and correcting transmission errors. It is commonly used by RAM chips that include forward error correction (FEC), which ensures all the data being sent to and from the RAM is transmitted correctly.

MicroDIMM

Micro Dual In-Line Memory Module - These are Smaller than SODIMM. Micro DIMMS are primarily used in note book (laptop) computers. Micro DIMMs are available in 144-pin SDRAM and 172-pin DDR. Each 172 Pin Micro DIMM provides a 64-bit data path. They are utilized in the latest laptop/notebook computers and networking applications that require high performance DDR memory.

Multi-channel Memory

Multi-channel memory, Dual-channel memory is a DDR, DDR2, or DDR3 chipset on the motherboard providing memory with two memory channels instead of one. The dual-channel platform helps alleviate bottlenecks that occur. Dual-channel lets one controller handle the reading and writing while the other controller prepares the next access thus preventing a delay.

RIMM

RIMM is computer memory that resembles DIMMs; however, it is 184-pin and is available with built-in ECC support and Non-ECC at speeds up to 800MHz. RIMM modules are commonly used on the Intel Pentium 4 motherboards. Unlike most other computer memory, computers that support RIMM require a continuous signal. If a memory socket is left empty, the computer will not work properly. Therefore, users must utilize C-RIMM modules in any slots that do not have RIMM modules.

SDRAM

SDRAM is an improvement to standard DRAM because it retrieves data alternately between two sets of memory. This eliminates the delay caused when one bank of memory addresses is shut down while another is prepared for reading.

DIMM

Stands for "Dual In-Line Memory Module." It is a type of computer memory. A DIMM is a small circuit board that holds memory chips. It uses a 64-bit bus to the memory

RAM

Stands for "Random Access Memory," RAM is made up of small memory chips that form a memory module. These modules are installed in the RAM slots on the motherboard of your computer.

SIMM

Stands for "Single In-Line Memory Module." This is an older type of computer memory. A SIMM is a small circuit board with a bunch of memory chips on it. SIMMs use a 32-bit bus,

SODIMM

Stands for "Small Outline Dual In-Line Memory Module." Most desktop computers have plenty of space for RAM chips, so the size of the memory modules is not a concern. However, with laptops, the size of the memory modules matters significantly. Because laptops are designed to be as small and as light as possible, the size of each component matters. In fact, laptop parts are so crammed together, large RAM chips often do not fit into the overall laptop design. This is why SO-DIMMs were created. A SO-DIMM is about half the length of a regular size DIMM. This allows greater flexibility in designing the memory slots for laptops. Many laptops have a user-accessible section that houses the SO-DIMMs, which make it easy to upgrade the computer's RAM. If the RAM chips were full size DIMMs, this type of design would be harder to incorporate and would likely increase the size of the laptop.

Partiy

mathematical term that defines a value as even or odd. For example, the number 4 has an even parity, while the number 5 has an odd parity. When even and odd values are compared, such as 4 and 5, they are considered to have different parity. If two even or odd values are compared with each other, they have the same parity.