RAM Inside and Out

[comseeker]

So I want to get 256 MB for a system I'm going to build: CUBX or BXMaster, running NT 4 Server and BackOffice Small Business Server. I'm not going to ask you which brand to buy... yet; I'm more concerned with understanding all of terms used to describe RAM so I know that I'm getting. If I go to ibuyer.net, for example, the different listings for Corsair modules is enough to spin my head. So let's start from the top...

UNBUFFERED: I only see listings for unbuffered RAM. Does that mean that all of the others are buffered? Which is better?
9 CHIP, 18 CHIP, 36 CHIP: I assume this refers to the number of memory chips actually on the RAM module. Do modules with more chips perform better? Are the ones with 36 chips too wide to fit into the RAM slots in a CUBX or BXMaster motherboard?
CAS 2, CAS 3, CL2, CL3: This, as I understand, refers to latency, and modules with less latency (CL2 or CAS2) have better performance. What is the performance difference? Is CAS2 (CL2) RAM on the order of being 30% or 5% faster overall? Does one need to change the settings in the BIOS to take advantage of CAS2 RAM?
REGISTERED: I have no clue on this one. What kind of benefit does one have with registered RAM?
ECC: This RAM can correct errors. Is it REALLY that helpful/effective? Is it slower than regular RAM?
FOR GX CHIPSET: Several Corsair modules, for example, were listed as for the the GX chipset. Will they still work in my BX-based system?

GENERAL INCONSISTENCIES: Take a look at the Corsair listings for PC100 ECC RAM (which is what I'm considering for my system--I'm not going to overclock it, so I have no need for PC133) at ibuyer.net (http://www.ibuyer.net/sprodcat.html?cid=851). Why is it that 256 MB 36 chip CAS3 Unbuffered RAM is ~$797 while a CAS2-based module is only ~645? Isn't CAS2 more desirable, and should therefore be more expensive? Why are these 36 chip modules $200-$400 more than their 18 chip counterparts?

BRAND SUGGESTIONS: I hear Corsair and Kingston make quality products. What about Crucial? They have a good deal on 256 MB PC100 ECC Registered RAM for $348.29 through their website. Kingston has 256 MB PC100 ECC Registered and Unregistered, CAS2 and CAS3 all for $365-371.

Thanks for your input.

 

[Howard]

The only thing I can help you with is the ECC part. Error correction is a MUST for servers, but slows down general performance. If it's not a server, don't get it.

 

[comseeker]

How much slower is ECC RAM compared to the regular RAM? Is it on the order of a few percent slower, or is it something much more significant?

 

[Midnight Rambler]

It's not significant enough to worry about.

I'd say go with the Crucial ECC. Crucial is high quality (as good as most Mushkin types, and def. better than Kingston), and they have great service and support.

And I hate to try and influence your mobo selection, but I'd seriously look at one of Intel's boards since you are not going to overclock and want max stability. They actually make some very sweet mobos ...

 

[IaPuP]

Woohoo..

I was declared "exhalted BIOS guru" the other day, perhaps today I can be "exhalted RAM guru".


>UNBUFFERED: I only see listings for unbuffered RAM. Does that mean
>that all of the others are buffered? Which is better?
I don't know about buffering. I get all the terms "tagged, buffered, etc" mixed up for some reason. I do remember that unbuffered is better and that buffered is either slower or less compatable.

>9 CHIP, 18 CHIP, 36 CHIP: I assume this refers to the number of
>memory chips actually on the RAM module. Do modules with more chips
>perform better?
Fewer chips are generally cheaper. The number of chips is not a problem, but usually there are 9 chips per bank. You have to be sure that your board supports the number of banks you want to use. Some only support 6 banks (so 4 double sided DIMMS will not work) but most BX boards support up to 8 banks.

>CAS 2, CAS 3, CL2, CL3: This, as I understand, refers to latency,
>and modules with less latency (CL2 or CAS2) have better performance.
>What is the performance difference? Is CAS2 (CL2) RAM on the order
>of being 30% or 5% faster overall? Does one need to change the
>settings in the BIOS to take advantage of CAS2 RAM?


>REGISTERED: I have no clue on this one. What kind of benefit does
>one have with registered RAM?
This is a compatability thing. You want to avoid it unless its necessary (don't remember why). It *is* necessary in 256MB DIMMS (for the BX chipset) and 512MB DIMMS (which I don't think the BX supports.

>ECC: This RAM can correct errors. Is it REALLY that
>helpful/effective? Is it slower than regular RAM?
It is useless to the average user. Hurts performance a little and drives cost WAY up.

>FOR GX CHIPSET: Several Corsair modules, for example, were listed as
>for the the GX chipset. Will they still work in my BX-based system?
I wouldn't chance it. If it says "for GX" it means its specifically designed for Intel Servers and you are better off with "regular RAM" because its usually faster and more compatable.

>GENERAL INCONSISTENCIES:
Only comments here: Buy what features you need and want don't pay more "because it costs more and must be better"

>BRAND SUGGESTIONS:
If you're not overclocking, anything with a good name chip on it: IE Micron, Infineon, etc will do ok. I have heard wonderful things about Mushkin and Crucial. I don't go for Kingston just because they sell it at Office Max (a bad sign?) *grin*

Its all depends on the board you're running, but only at 100MHz, there isn't much RAM that isn't up to the task.


Let me tell you this. I believe ECC is a ripoff. Honestly, I've seen long-term stability tests (over 6 months) reveal that there is no extra stability from servers (in certain conditions). Only under heavy load and VERY harsh environmental conditions is it really a *necessity* in my opinion.

Eric