tweek43110

This is my first faq and it will cover all the RAM types (to my knowledge)
I'll start with the old stuff moving into the more modern.

DRAM (Dynamic Random Access Memory)
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DIPP (Dual Inline Pin Package):
This RAM connected directly to the motherboard,only one bit wide, because of this RAM had to be filled in by rows to match the CPU (Intel 8088=8-Bit external data bus=8 individual RAM chips per row)

30-Pin SIPP (Single Inline Pin Package):
The first "popular" RAM stick. 4-Bits wide. Made installing and removing RAM much simpler by putting the chips onto a stick.

30-Pin SIMM (Single Inline Memory Module):
Replaced the SIPP with an even easier to install stick (no pointy,easily breakable pins). These were each 8-Bits wide.

72-Pin SIMM:
The next generation of SIMMs. These made higher memory capacity possible and were upped to 32-Bits wide.

DIMM (Dual Inline Memory Module):
come in many pin packages, generally 168 and 184-Pin.These were brought to 64-Bits wide.

SO-DIMM (Small Outline-DIMM)
Used in laptops and notebooks and are available in 72,144,and 200-Pin packages. With the exception of the 72-Pin SO-DIMMs (32-Bit) these were also 64-Bits wide.

EDO DRAM (Extended Data Out DRAM):
An improvement on FPM RAM. Was refreshed less often, giving and extended amount of time data could be pulled from the RAM.

SDRAM (Synchronous DRAM):
Synchronous meaning it is tied to the pcs clock, whereas FPM and EDO were Asynchronous. This also means that you had to buy ram that would match the clock speed of the CPU.

RDRAM (Rambus DRAM):
Made by Intel to match the speeds of their pentium 4s. Capable of speeds up to 800mhz. Used RIMMs AND CRIMMs.RIMMS have to be installed in pairs,because they were 64-Bits wide, and unfilled banks had to be filled with CRIMMS (Continuity Modules).

DDR SDRAM (Double Data Rate SDRAM):
Very common in PCs today, pushed by AMD for their Athlons.Does two operations per clock cycle. Run at many speeds, most commonly 200,266,333, and 400mhz.

DDR2 SDRAM (Double Data Rate 2 SDRAM):
The difference of DDR2 to DDR is a doubled bus frequency for the same physical clock rate, thus doubling the effective data rate another time, in other words 4 operations per cycle

DDR3 SDRAM (Double Data Rate 3 SDRAM):
Currently in development.Will bring it to 8 operations per clock cycle.
http://en.wikipedia.org/wiki/DDR3_SDRAM

OTHER INFO
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Ram Banks:
One Bank=Width(# of bits) of the CPUs external data bus/Width of the SIMM or DIMM

Parity/Non-Parity:
Can be told by the # of chips on the stick, and odd amount is parity while an even amount is non-parity. Parity RAM has the ability to identify problems on a RAM stick, but cannot correct the error.

ECC RAM (Error Correction Code):
Improvement on parity RAM, can identify and correct problems on the fly.

Ill take any feedback and corrections.