|
 |
|
|
|
Memory Module Picture Guide
|
Tuesday, October 17, 2000
Introduction
In the early mid-1980s, PC memories consisted primarily of memory chips in dual in-line packages which were either soldered down or installed in DIP sockets.
Both of these memory solutions were difficult to upgrades , repair and takes up large amount of board space.Other alternate memory solutions-such as memory expansion cards-also proved to be only a temporary solutions, as the I/O bus performance quickly became an impediment to the "high speed" memory devices of that time.
The first true memory module was the 8 or 9-bit , 30-pin single in-line memory module (SIMM), which offered a low-cost pluggable memory solution that was ideally suited for the 1- and 2-byte processors of that time. Widely adopted by the late 1980s, this product began to peak in the early 1990s, with the adoption of 4-byte processors, requiring four 30-pin SIMMs to accomplish a single upgrade increment.
Following the 30-pin SIMM was the 72-pin SIMM, offering 32 to 40 bits of data (4 bytes) an board area only 20% larger than a single 30-pin SIMM.
Learning from the 30- and 72-pin SIMM families, memory and system developers were determined to develop more robust memory solutions that could better balance the tradeoffs between cost, performance and reliability.
From this activity the current “mainstream” memory module solutions, the 168pin memory “dual in Line memory modules or DIMMs are more suited for the high performance Intel-Pentium processor.
This article will take you through the different type of memory module available both current and older memory solutions that are still used in some of the older computer system.
Types of Memory Module
30 Pin SIMMs
* The 30 Pin SIMMs was the 1st generation SIMM memory which are typically found in older Intel 286 and 386 desktop computer system.
* The 30pin SIMM module comes in both 8 bit and 9 bit(parity) configuration and memory capacity range from 256K to 8 megabyte.
* 30pin SIMM comes in only 5 Volts and speed range from 60ns to 80ns.
* The DRAM types supported are mostly Page Mode and Nibble Mode DRAM which comes in both DIP, PLCC and SOJ package
72 Pin SIMMs
* 72pin SIMMs are typically found in the Intel 486/486DX,586 and Pentium-Pro desktop computer system.
* The 72pin SIMM module comes in both 32 bit and 36 bit(parity) configuration and memory capacity range from 4,8,16 to 32 megabyte.
* 72pin SIMM are offered in two voltage - 5V and 3.3V and speed range from 60ns to 70ns.
* Fast page mode and EDO are the standard DRAM type offered in this option.
* Dram chip package offered comes in DIP,PLCC and SOJ packages.
168 Pin DIMM
* 168 PIN DIMMs are mostly used in most desktop systems manufactured today.
* Two different types of memory technology are being offered - EDO/FPM DRAM and the Syncronous DRAM are normally packaged in this DIMM form factor.
* The 168pin DIMM module comes in three configuration 64bit, 72bit and 80Bit(ECC) configuration and memory capacity range from 16,32,64 to 1000 megabyte.
* Two voltage are offered :
- EDO/FPM = 3.3V and 5V
- SDRAM = 3.3V only
* 168pin DIMM added features is the inclusion of a serial eeprom called the "Serial Presence Detects" which contains information about the module type.
* 168 DIMM which uses SDRAM memory can reach a maximum frequency of 150Mhz, without crashing the PC systems.
* 168pin DIMMs are also offered in two configuration for different PC applicaiton - Register DIMM or Buffered DIMM for Servers and Unbuffered DIMM for PC.
72 Pin SODIMM
* 72pin SODIMMs are typically used in the Pentium-II Laptop computer system.
* The 72pin SODIMM module comes in 64 bit configuration and memory capacity range from 8,16 to 32 megabyte.
* For low power application only one voltage are offered : EDO/FPM = 3.3V
* Fast page mode and EDO are the standard DRAM type offered in this option.
* EDO/FPM DRAM chip package offered comes in SOJ packages.
144 Pin SODIMM
* 144 SODIMMs are typically used in the PC66 and PC100 SDRAM Laptop compatibile computers.
* The 144pin SODIMM module comes in both 64 bit and 72bit ECC configuration and memory capacity range from 16 to 256 megabyte.
* SDRAM chips used on the 144 SODIMM are typically SDRAM made in TSOP package and comes in 3.3V only.
100 Pin DIMM
* 100 PIN DIMMs are primarily used in printers.
* The 100pin DIMM module comes in both 64 bit and 72bit ECC configuration and memory capacity range from 16 to 128 megabyte.
* SDRAM chips used on the 100 DIMM are typically SDRAM made in TSOP package.
* EDO/Page mode DRAM are also used on 100pin DIMM.
144 Pin Micro-DIMM
* 144 PIN Micro-DIMMs are primarily used in digital assistants, subnotebooks and notebook computers.
* The 144pin Micro-DIMM module comes in 64 bit configuration and memory capacity range from 46 to 128 megabyte.
* DRAM Chips used on the 144 Micro-DIMM are typically SDRAM made in TSOP package, DDR SDRAM will be available soon.
184 Pin RIMM
* The 184 pin RIMM are used in the latest Intel 820/840/850 Rambus PC System.
* The 184 pin RIMM module comes in both 16bit and 18bit ECC configuration and memory capacity range from 64 to 512 megabyte.
* The rambus memory chip is package in a Ball Grid Array (BGA) form factor.
* One of the key features of Rambus memory is its high operating frequency which comes in grades of 600,700 and 800Mhz.
* Power needed to drive the rambus chip is only 2.5 Volts
* The 1 Ghz Rambus chip is under development and is slated to be launched next year 2001.
184 Pin DIMM
* The 184 Pin DIMM is the up and coming mainstream memory technology which supports DDR SDRAM on Intel P4 i845 chipset.
* The main difference between the regular sdram vs ddr sdram is its capability to read/write data on both edges of a clock, therefore resulting in a faster data transfer.
* DDR memory comes in several frequency - 200Mhz, 266Mhz,300Mhz and 333Mhz and operates at 2.5 Volts.
* The 184pin DIMM module comes in both 64 bit and 72bit ECC configuration and memory capacity range from 64 megabyte up to 1 gigabyte.
PC2100 or 266Mhz Unbuffered JEDEC DIMM DDR Module
PC2400 or 300Mhz DIMM DDR Module
* DDR SDRAM chips used on the 184 DIMM are typically SDRAM made in TSOP package.
200 Pin SODIMM
** The 200pin SODIMM module comes in both 64 bit and 72bit ECC configuration and memory capacity range from 64 megabyte up to 512 megabyte.
** DDR SDRAM chips used on the 184 DIMM are typically SDRAM made in TSOP package.
** DDR SODIMM module will be used in the next DDR Laptop Application.
General disclaimer: This page only reflects the author personal opinion and assumes no responsibility whatsoever regarding any of the contents or any damages that may occur explicitly or implicitly from reading the contents of this site. All names and trademarks mentioned in this review are the exclusive property of the respective parent companies.
Copyright 2002 CST Inc
By: DocMemory
Copyright © 2023 CST, Inc. All Rights Reserved
|
|
|
|
