ddr question

[debgk]

Looking at DDR ram ... I saw these different varieties listed with different sizes ... (cut and pasted from a site)

Can anyone help me figure out what this means? Do different boards take different types of DDR ram?? How would I know which board took which type?? Haven't seen it specified with boards that I've looked at ... thanks!

here's my confusion:

DDR PC2100 128MB 2.5V 16x64 ECC

DDR PC2100 256MB 2.5V 16x8

DDR PC2100 256MB 2.5V 16x8 ECC

DDR PC2100 256MB 2.5V 16x8 ECC REG

DDR PC2100 512MB 2.5V

deb

 

[Guest]

Anyone feel free to correct me if I’m wrong on any of this, but to my knowledge…


DDR SDRAM-(Double Data Rate) allows for data to be retrieved on both the rising and falling edges of the clock instead of just on the rising edge, in effect doubling the transfer rate of the clock.

PC2100-(is the speed) Running at 133mhz DDR to achieve 266mhz with an output of 2.1GB /s

128MB- 128 MB of memory on the chip

2.5v- 2.5 volts

16x64- is the architecture of the chip

ECC- chip has error checking

Check with your motherboard manual to see what it will support.


sudden unexpected cessation of computer activity with a sudden unexpected increase in user activity=

 

[tilepusher]

Hey D,
I think what you need to know is: DDR PC2100 = DDR ram running with a 2.1 gigabyte bandwidth(bigger the better, if your system can use it) at 266 mhz. There is other flavors like PC 1600- 1.6 gb bandwidth at 200 mhz, PC 2400(not supported yet, for over-clocking only) 2.4 gb at 300 mhz, and PC 2700(soon to be the new standard, for SiS & Via chipsets supporting the Intel P4 right now) 2.7 gb at 333mhz. 128MB, 256MB & 512MB all refer to the capacity of the module.... I would stay away from the 512MB modules for now, due to non standard build quality. Anything that is labeled "ECC" is for Servers in general and Slower...don't use it. Lastly not listed is "CL" or "CAS" this is important, the lower the number the faster the ram. Right now CAS 2.5 seems to be standard for PC 2100. If you want better performance get CAS 2. Oh yeah "REG" stands for Registered, like everything else check your mobo specs for the recommend types of DDR. Good Luck.
Peace Out..........tile

I'm not 1/2 as smart as I think I am and less than 1% smart as I tell people I am.

 

[camieabz]

PC2100 = 266MHz FSB (133 DDR) for Athlons @ 266.

128,256,512 = Capacity in Megabytes of the RAM chip.

2.5V = Voltage the memory runs at.

16x64 etc. = physical chip architecture. Don't worry about this.

ECC = Error correction RAM. Used with servers for stablity and reliability, but can be slower than non-ECC RAM. Not needed for most users.

REG = Registered memory. Someone else can enlighten on this one.

<b><font color=blue>~scribble~</font color=blue></b>

 

[Arbee]

Straight from crucial FAQ (yep, I'm lazy):

"The term "registered" refers to how the memory module processes signals. Registered modules contain a register that delays all information transferred to the module by one clock cycle. This type of memory is primarily used in servers and was designed for modules with 32 or more chips on them to help ensure that data is properly handled."

Translation: it is buffered memory (update: not really - it has a register that delays it, but anyway...) - slower and more stable, useful for largely populated DIMMs (32+ memory modules per DIMM) specially for servers (that usually require large memory amounts).

For regular PCs (for work and leisure) use unbufered DIMMs.


How terrible is wisdom when it brings no profit to the wise<P ID="edit"><FONT SIZE=-1><EM>Edited by Arbee on 09/09/01 11:41 AM.</EM></FONT></P>