question about ram...

[cluelessnewbie]

Today I went to cruical to buy some ram but then I saw this :

DDR PC2100 CL=2.5 Unbuffered Non-parity 2.5V 32Meg x 64
And then i saw this
DDR PC2100 CL=2.5 Unbuffered Non-parity 2.5V 32Meg x 72

Can someone tell me the difference??

also, what does that CL mean? b/c on a ddr pc1600, i saw that the CL = 2 instead of cl=2.5 like pc2100

[cluelessnewbie]

actually the second DDR pc2100 was

DDR PC2100 CL=2.5 Unbuffered ECC 2.5V 32Meg x 72

basically, it was ECC instead of non-parity... what's the difference there as well?

thx in advance

[cluelessnewbie]

Alright, I messed up with the configuration of the those DDR ram... let me start over

DDR PC2100 CL=2.5 Registered ECC 2.5V 32Meg x 72

vs.

DDR PC2100 CL=2.5 Unbuffered Non-parity 2.5V 32Meg x 64

can someone tell me difference? Also, could someone answer my CL question in the first post ? thx =)

[Kuasimodem]

You need to know if your motherboard requires ECC (error correcting) RAM before you decide which RAM to buy, check your manual to find out.

The CL is CAS Latency (http://www.corsairmicro.com/main/trg-cas.html) , it has to do with how fast the RAM is, the lower the CAS or CL number, the better.

<edit> You got me to wondering if I was thinking right, so I had to do some research... Google (http://www.google.com) is a great search engine!!! http://www.sysopt.com/forum/smile.gif

[This message has been edited by Kuasimodem (edited 06-12-2001).]

[cluelessnewbie]

alright could someone explain the difference between x 72 and x 64
and also the difference between registered and unbuffered ?? thx alot

[Kuasimodem]

Sorry about that, ECC or registered RAM uses 8 extra bits for the error correction function, that is why it's listed as x72 instead of x64.

Here's (http://www.zdwebopedia.com/TERM/E/ECC_memory.html) some info.

And more (http://support.kdupg.edu.my/IT%20DICTIONARY/TERMS/ECC%20RAM.htm)

I love google!

Curt

[cluelessnewbie]

Thx alot but I have one more question, What's the difference between registered and unbuffered??

[Bovon]

Registered ram has extra chips onboard. One of the functions of the registered chips is being drivers for the ram. Normally, the northbridge drives the ram, but if the ram mb gets so large, the north bridge can't drive them all and will overheat and fry its self trying. So, the northbridge drives the register chips, which then drive the ram chips. Registered and Error Checking ram are only used in servers. They both take extra cycles to process information, and make the operation slower. Most mainboards for our type of use, (desktops) take unbuffered and non parity ram.