Memory Modules Specifications

Help with Memory Modules specifications:

General Specifications

	Memory Type:
	Your choices are...
	RAM		Random access memory (RAM) can be read from or written to in a nonlinear manner. RAM derives its name from the fact that any byte of memory can be accessed randomly instead of sequentially. RAM does not retain data in memory when power is removed.
	DRAM		Dynamic RAM (DRAM) stores each bit of data in a separate capacitor. DRAM derives its name from the fact that it must be refreshed periodically. Because of the way in which the memory cells are constructed, the reading action refreshes the contents of the memory. DRAM loses its data when the power supply is removed.
	FPM RAM		Fast page mode (FPM) RAM does not require a row address if the data is located in the previously accessed row. An older form of RAM, FPM RAM is being replaced by newer technologies such as EDO RAM.
	EDO RAM		Extended data out (EDO) RAM retrieves the next block of memory while sending the previous block to the CPU. EDO RAM is faster than FPM RAM and designed for bus speeds up to 66 MHz.
	BEDO RAM		Burst extended data out (BEDO) RAM processes large blocks of data in an uninterrupted burst of smaller units. Each burst carries information about consecutive memory locations. BEDO RAM can handle four data elements in a single burst, enabling the last three elements to avoid the delays experienced by the first. BEDO RAM is suitable for bus speeds up to 66 MHz and can read data large blocks more quickly than EDO RAM.
	SRAM		Static RAM (SRAM) is more expensive than DRAM, but faster and more reliable. Unlike DRAM, SRAM does not need to be refreshed constantly; SRAM is refreshed only when a write command is performed. SRAM is most commonly used in the L2 cache for PCs. There are two types of SRAM: synchronous and asynchronous. Synchronous RAM is synchronized with the system clock. Asynchronous RAM is not.
	L2 Cache		The level two (L2) cache is a memory area separate from both the level one (L1) cache and the CPU. Data searches begin in the L1 cache, move to the L2 cache, then to DRAM, and finally to physical storage. Data is transmitted from the processor chip into main memory though the L2 cache. The L2 cache uses SRAM and aligns memory access speeds with the speed of the CPU itself.
	Asynchronous SRAM		Asynchronous static RAM (SRAM) is not synchronized with the system clock. It is slower than synchronous SRAM.
	Synchronous SRAM		Synchronous SRAM is synchronized with the system clock. It is faster than asynchronous SRAM and provides speeds up to about 8.5 ns.
	PB SRAM		Pipeline burst (PB) SRAM executes requests within a burst on a nearly instantaneous basis. PB SRAM is designed to work with bus speeds of 75 MHz and higher.
	WRAM		Windows RAM (WRAM) is a dual-port RAM used exclusively in graphical displays. WRAM is similar to VRAM, but provides up to 25% more bandwidth. WRAM includes a double-buffering data system that is several times faster than VRAM, resulting in considerably faster screen refresh rates.
	SGRAM		Synchronous graphics RAM (SGRAM) is a single-port RAM used primarily with video accelerator cards. To improve performance, a dual-bank feature opens two memory pages simultaneously. SGRAM is used in 3-D video technology because its block-feature speeds screen fills and allows fast memory clearing. Three-dimensional video requires extremely fast clearing, in the range of 30 to 40 times per second.
	ROM		Read-only memory (ROM) contains pre-programmed data and either cannot be changed or requires a special operation to overwrite. ROM retains data in memory when power is removed. A photosensitive material is etched to hold the required bit pattern.
	PROM		Programmable ROM (PROM) can be written to only once, after which the contents cannot be changed.
	EPROM		Erasable programmable read-only memory (EPROM) is a type of PROM that can be erased through exposure to ultraviolet light and then reprogrammed.
	MASK ROM		MASK ROM is a type of read-only memory (ROM) that can be programmed only once. Manufacturers that produce high volumes of semiconductors often use MASK ROM because it is the most cost-effective ROM available.
	Other		Other unlisted memory types.
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	Form Factor:		The form factor of any memory module describes its size and pin configuration. Most computer systems have memory sockets that can accept only one form factor.
	Your choices are...
	DIMM		Dual in-line memory module (DIMM) provides a 64-bit data path. DIMMs can perform the functions of two single in-line memory modules (SIMMs). Typically, Pentium® processors use a single DIMM instead of two SIMMs. Pentium is a registered trademark of Intel Corporation.
	SO DIMM		Small outline, dual In-line memory modules (SO DIMM) are enhanced versions of standard DIMM. SO DIMMs are about half the length of a typical 72-pin SIMM. These compact DIMMs are used in mobile computing devices. SO DIMMs come in a variety of pin sizes and can be installed either singly to support 32-bit systems, or in pairs to support 64-bit systems.
	uDIMM		Micro single inline memory module (uDIMM).
	AIMM		Accelerated (or advanced) graphics ports (AGP) in-line memory modules (AIMM) allow the graphics controller to directly access texture map data from the main memory rather than having to move it to the graphic controllers' local memory first. This helps increase system speed for processing graphics and allows for a use of a larger portion of memory by "borrowing" storage for texture maps from main memory.
	RIMM		Rambus inline memory modules (RIMM) are designed to install Rambus DRAM (RDRAM).
	SO RIMM		Small outline Rambus inline memory modules (SORIMM) have a smaller profile that standard RIMMs and are used in laptop computers and systems that have strict size requirements.
	SIMM		Single in-line memory module (SIMM) provides a 32-bit data path. Devices that require wider data paths, such as Pentium® processors, use a pair of SIMMs. Slower processors use a single SIMM. Pentium is a registered trademark of Intel Corporation.
	Card		The memory is in a card configuration.
	Other		Other unlisted form factor.
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Performance Specifications

	Capacity:		The amount of data that can be transmitted over a specific period of time.
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	Clock Speed:		Clock speed is the raw MHz that the CPU (Central Processor Unit) operates at. For example, an AMD Athlon 1GHz has an operating clock speed of 1000 MHz; this is the processor's clock speed.
	Search Logic:		User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria.
	Cycle Time:		The length of time it takes to transmit data expressed in terms of the minimum amount of time required for a memory to complete a cycle such as read, write, read/write, or read/modify/write.
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Power Characteristics

	Supply Voltage:
	Your choices are...
	-5 V		The chip operates with -5 volts.
	-4.5 V		The chip operates with -4.5 volts.
	-3.3 V		The chip operates with -3.3 volts.
	-3 V		The chip operates with -3 volts.
	1.2 V		The chip operates with 1.2 volts.
	1.5 V		The chip operates with 1.5 volts.
	1.8 V		The chip operates with 1.8 volts.
	2.5 V		The chip operates with 2.5 volts.
	2.7 V		The chip operates with 2.7 volts.
	3 V		The chip operates with 3 volts.
	3.3 V		The chip operates with 3.3 volts.
	3.6 V		The chip operates with 3.6 volts.
	5 V		The chip operates with 5 volts.
	Other		Other unlisted supply voltages.
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General Features

	JEDEC Standard Compatible		Joint Electronic Devices Engineering Council (JEDEC) is an international body of Semiconductor manufacturers that set integrated circuit standards.
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	Radiation Tolerant		The device is radiation hardened or tolerant.
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	ESD Protection		Electrostatic Discharge Protection (ESD) is the dissipation of electricity. ESD can easily destroy semiconductor products, even when the discharge is too small to be felt.
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Applications and Features

	Applications:
	Your choices are...
	Personal Computing		The memory may be used in a personal computer.
	Motherboards and RAID Cards		The memory is meant to expand the memory of motherboards or RAID cards.
	Digital Electronics		The memory may be used in digital electronics like cameras.
	Servers and Networking		The memory is meant to expand the capacity of servers and other network components.
	Printers and Imaging		The memory is meant to expand the capacity of printers and imaging components.
	Other		Other unlisted application type.
	Search Logic:		All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
	Error Checking and Correction
	Your choices are...
	Parity		As data moves through a computer (e.g. from the CPU to the main Memory), the possibility of errors can occur, particularly in older 386 and 486 machines. Parity error detection was developed to notify the user of any data errors. By adding a single bit to each byte of data, this bit is responsible for checking the integrity of the other 8 bits while the byte is moved or stored. Once a single-bit error is detected, the user receives an error notification; however, parity checking only notifies, and does not correct a failed data bit. If your SIMM module has 3, 6, 9, 12, 18, or 36 chips then it is more than likely parity.
	Error Checking Parity		Error checking and correction (ECC) modules have an extra chip that detects if the data was correctly read or written by the memory module. If the data wasn't properly written, the extra chip will correct it in many cases (depending on what type of error).
	Nonparity		Non-parity (also called non-ECC) modules do not have an error-detecting feature.
	Search Logic:		Products with the selected attribute will be returned as matches. Leaving or selecting "No Preference" will not limit the search criteria for this question; products with all attribute options will be returned as matches.

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