Memory Chips & M/Board Chip
sets:
CHIP's Explained:
Also, read my Memory Page---ok.
What kind do you have--huh:
SIMMs, DIMMs, DRAM, ESDRAM, FRAM, SDRAM, FMP, EDO, SDRAM II, DDR, RDRAM, SLDRAM???
SIMM=
Single line memory modules (most popular and the old version) of dimm. These memory cards
come in 30 & 72 pin config's and contain FPM or EDO ram with a outside data flow limit
of 32 bits.
DIMM=
Newer version of simm and it's a dual in-line memory module. These come in 72, 144, and
168 pin config's and come with Pentium's hopefully and there limit is 64 bits.
DRAM=
Has transistors and capacitors to retain data and are slower and not very
dependable---plainly said (Cheaper).
ESDRAM=
The ESDRAM, developed and marketed by Ramtron's wholly owned subsidiary, Enhanced Memory
Systems, Inc. (Enhanced), is a high-performance version of the popular synchronous DRAM
(SDRAM) that includes Ramtron patented technology to achieve market leading performance.
Sample evaluations by Enhanced have proven EDRAM operation at 200 MHz memory burst speed -
performance that has not been achieved by any other SDRAM memory device. In addition, the
combination of faster latency and high burst speed allows the ESDRAM to deliver more than
two times the sustained bandwidth of the prevailing PC-100 SDRAM or Direct Rambus DRAM
devices. The ESDRAM product is being manufactured for Enhanced by Siemens Semiconductors
and IBM Microelectronics.
FPM=
Fast page mode started about 4 years ago (see simm).
EDO=
Extended data out started (I think) in 1995 and is measured in nanoseconds (see simm).
SDRAM=
Synchronnous ram started in 1997 and measures in clock speeds.
ESDRAM, FRAM, SDRAM II, DDR, RDRAM & SLDRAM=
These are new technologies and our future answers we hope. As quoted somewhere (and I
don't remember) these chips are ready just waiting for the MotherBoard MFG's to catch up.
SLDRAM performance can be cranked up to 800Mhz, Fram Technology will be a blazing 100
times faster than existing flash memory.
EEPROM on SDRAM:
EEPROM stands for Electronic Erasable Programmable Read
Only Memory. It is used on the SDRAM to store some configuration information about SDRAM
itself. This feature, known as Serial Presence Detect (SPD), allows the i440LX chipset and
BIOS to determine the type of memory installed in the system, resulting in optimal system
performance.
Some motherboards require the EEPROM in order to function with the SDRAM memory (Intel's
AL440LX). If your board doesn't require EEPROM, it will just be ignored. When you purchase
SDRAM, you should ensure that there is EEPROM on it.
PC100 Compliant:
Some SDRAM that are rated as 10ns or 100Mhz may make your system unstable if your system
is running at 100Mhz bus speed. This is because the environment of your PC may be filled
with magnetive wave or radiation which may affect your memory when your memory is running
at its limitation (100Mhz). Some motherboard, like A-trend 440BX, even supports 103Mhz and
112Mhz bus speed, so it is a good idea to buy a 6ns(for up to 166Mhz bus speed) or
7ns(142Mhz bus speed) PC100 SDRAM for the best quality of your high performance system. If
you can not find 6ns or 7ns PC100 SDRAM, then 8ns (125Mhz) is also good enough.
Mother/Board Chip Sets:
Here's a bunch of URL's where you can get the information.
http://www.mkdata.dk/english/module2d.htm#TX
http://users.aol.com/robincomp/links.html
http://www.accelerated.ca/tx-pro.html
http://www.intel.com/support/etherexpress/pro100/6451.htm
http://www.unicomplabs.com/Support/driver.asp
http://www.cs.mtsu.edu/~alovett/
A Bit of CHIP History!!
Memory chips, otherwise known as DRAM (Dynamic Random Access
Memory), are the small black chips which are mounted on each module. On the surface of
these chips are a series of letters and numbers which identify the density, speed, date of
manufacture, etc. which we need to know.
This "code" usually starts out with a set of letters and/or a logo and is
followed by a string of numbers, ie. NEC421000-70L. The initial letters describe the
manufacturer of the chips - in this example, the product was made by NEC. The numbers
which follow describe the density of the chip - in this case, the chip is a 1M x 1
configuration. Finally, the ending number will describe the speed of the chip, ie. -70L.
This means the chip is rated at 70 nanoseconds. Often, the trailing "0" is left
off and is shown as a -6, -7 or -8 which indicate speeds of 60, 70 or 80 nanoseconds
respectively.
The Number of Pins and Chips on Each Module
The two most common types of memory modules are 30 pin and 72 pin SIMMs (Single Inline Memory Modules): 30 pin SIMMs most often come in 256Kb, 1Mb and 4Mb varieties. The number of chips on modules of these kinds are usually 2 or 8 (non-parity) or 3 or 9 (parity). In the case of the 3 chip SIMMs, 2 of the chips are identical and the third is different. This is the lower density "parity" chip.
72 pin SIMMs typically come in 4Mb, 8Mb, 16Mb and 32Mb varieties. Non-parity 72 pin SIMMs usually have only one kind of chip mounted onto the surface(s) of the module. For example, a 4Mb non-parity SIMM will have 8 identical chips on one side of the module. An 8Mb non-parity SIMM often has 16 identical chips - 8 chips on each side.
72 pin SIMMs with parity are likely to have two varieties of chips on board. For example, a 4Mb SIMM may have 8 identical chips on one side and 4 identical chips of another type on the other side.
It is important to know the difference between parity vs. non-parity SIMMs before requesting a quotation.
Understand Your Motherboard's Expansion Capabilities
In addition to having the above information on hand, it is equally important to know how much you can physically expand the memory on your system's motherboard. It is to your benefit to either consult the manual which accompanied your system and/or have a look at the actual motherboard in order to see how many vacant slots or banks of slots are available in which to install additional memory.
For example, if your system utilizes 30 pin modules and you currently have 4Mb of total memory, you likely have 4 modules of 1Mb SIMMs installed. It may be, therefore, that to upgrade to 8Mb of RAM, you simply need to add 4 more 1Mb SIMMs into 4 remaining (vacant) slots. However, if there are only 4 slots on your motherboard, and they are occupied by your present memory, you will need to assess your upgrade options.
As of this Day April 28, 1999
Corsair Micron PC133 Rules the world of RAM Memory chips---period......
