Worth getting Registered ECC RAM over Unbuffered Non Parity?

[snow patrol]

All this talk of RAM has led me to the decision that the time has come for me to upgrade my PC100 128meg DIMM to a 256Meg Cas 2 crucial DIMM. I'll be buying direct from the site, but there's two options I could go for:



Cheaper Cas 2 (unbuffered, non parity)
or;

More expensive Cas 2 (Registered, ECC)

What's the difference? Any suggestions as to whether no.2 is really worth ~25% more than no.1?

Thanks for any feedback

 

[AndyHui]

Unbuffered non-parity is the stuff that we usually use.

ECC RAM is generally only used in servers to ensure data integrity. These days RAM is reliable enough not to need it for normal usage.

ECC also takes a minor hit to performance; I don't think the additional costs are worth the gains in a non-server environment.

 

[snow patrol]

Thanks for the reply Andy. So you're saying that ECC is actually slower than the cheaper stuff?

Well then, I guess I'll go for the 'el cheapo' stuff

 

[nippyjun]

Personally I wouldn't spend money on your ram right now unless you just need more. DDR ram is getting cheaper and so will RDram.

 

[snow patrol]

Rambus? Lol, as if

Also, I don't have a DDR mobo, and I don't want to upgrade my CPU/motherboard just yet.

 

[ruckb]

Hi snowPatrol,

check this thread, there is a lot of info included:

ECC Thread

ruckb

 

[polar]

before you make the purchase, make sure that your mobo supports ECC ram. as far as i know, 815 mobos don't support it.

 

[snow patrol]

Thanks for the link ruckb.

Btw Polar, I decided that I'm not going to get ECC ram

 

[MadRat]

ECC RAM is actaully faster. The 4-bits of parity are at zero performance cost.

 

[Oyeve]

I use ECC but am thinking I made a decision. I cant find a board that meets my specs that can use ECC.

 

[Mem]

Snow patrol go with unbuffered,btw I also purchased mine from Crucial UK,anyway if you do get problems they will test it free of charge(I had mine tested last year).

 

[ruckb]

Hi MedRat,

take a look at the link I gave above.

ECC is a little bit slower then non ECC !

ruckb

 

[TravisBickle]

random and infrequent memory errors can be cause by cosmic rays. the more memory you have, the more often they occur. however, you could go for months without an error.
you could cure it by working in underground bunkers, or use ECC. but I think that any performance hit is not what the gamers and braggers want.

 

[Oyeve]

Just get the best damn memory you can afford! Sheesh!

 

[MadRat]

Hmmm, if it transfers 68 bits of data per second versus 64 bits of data per second, which one is faster? The compare is done on the chipset level where it is does not slow down memory speed. Its argueing apples and oranges.

 

[andylawcc]

I thought Registered Ram have different hinges places (the 3 holes in between the 168 pins) so it MAY not fit in NON REGISTERED ram slot mobos, and i815 definitely supports ECC.

and I thought 72 bit = ECC.

 

[pm]

There are quite a few mistakes in this thread:

1. Registered memory requires a motherboard that only takes registered memory. Snow Patrol, if your motherboard does not currently use registered memory, you cannot upgrade to it. Registered memory can be faster in some implementations than non-registered, but usually the difference is negligible. The main advantage of registered memory is that you can have more DIMM slots than 4 for PC100 or 3 for PC133 (note that any non-registered motherboard with 4 PC133 slots is technically violating the PC133 spec).

2. ECC is slightly slower than non-ECC memory (~1% slower, there's a 2 cycle hit for read-after-modified writes). ECC is 72-bits. A paper presented by a researcher at IBM says that you could expect a memory error in a bank of 256MB once per month at sea level. This is probably a little high. Being at a higher elevation will increase the liklihood of a hit. Personally, I think anyone for whom data integrity is very important should pay the small upgrade cost for ECC. If you think that you need to back up your data frequently, then you probably should pay for ECC as well.

3. The i815 motherboard supports ECC. Every major chipset released recently that I am aware of supports ECC. I've been working on a program to track ECC events and have been writing in support for other chipsets, so I have looked into this pretty thoroughly.


Oyeve, what chipsets were you looking at? I can tell you if they have ECC support.

 

[sitka]

Is it true that the "registered" part in registered improves the voltage deliver along the fsb or is that buffering.

 

[urameatball]

registered ECC ram have different hinges and contact points and don't work for motherboards that don't specify that they NEED registered ECC memory. The only motherboards that support registered ECC memory that I've seen are those high end server boards that actually require that type of stability. I think ALL dual Socket370 motherboards use Registered ECC ram though.

 

[snow patrol]

Thanks again for all the feedback guys.

Where would I be without this place?

 

[AndyHui]

pm: Sorry, I would have to disagree with you there regarding ECC support on the i815(E/P) chipsets.

None of the Intel Value/Mainstream chipsets support ECC SDRAM, and have not done so since the time of the original stripped down EX chipset. See this table. The only current Intel chipsets to support ECC SDRAM are the 440BX, i820, i840 and i850. The i810 and i815 families do not, along with the 440EX and 440ZX.

 

[pm]

Oops. I stand corrected. Andy's right.

I do have an entry in my table for the i815, but it's supposed to say "no support".

 

[Spears]

Hello,

I've read lots of postings regarding ECC memory performing slower than non-ECC memory from a system memory performance perspective. Most of these postings say it, but don't really give any further useful information. I've just purchased 2 Crucial 128MB PC133 CL2 ECC memory sticks for my home system and payed $3.50 per stick for the ECC capability. At some point in the next year these sticks will be migrated to a full time server running Linux. Please, enlighten me with a few more answers, please.

Question #1:
Can somebody point my to ECC vs. non-ECC benchmarks in typical home systems? (say PIII-850MHz, 256MB, running Win98 or WinNT)

Question #2:
If I use ECC memory in a BX6-R2 motherboard, and disable ECC in the BIOS will the performance be the same as the non-ECC memory?

Thanks,

-Dan