PDA

View Full Version : Why ECC Ram ?



eva2000
08-12-2003, 03:49 AM
Just thought this was useful to post as i posted at another forum asking about it

why ECC ram ?

http://www.pcworld.com/howto/article/0,aid,110401,00.asp



Q: What's ECC RAM, and should I buy it?

A: Error-Correcting-Code RAM modules have special circuitry that corrects memory errors on the fly. They're used primarily in servers and high-end workstations. ECC SDRAM will work in non-ECC motherboards, but you won't get the benefit of the ECC circuitry, so it doesn't make sense to pay the extra cost.



http://www.memorysuppliers.com/eccwhatisita.html



First of all, what does ECC stand for?

"ECC" stands for "Error Checking and Correction".

And, what is "Error Checking and Correction"?

Error Checking and Correction refers to a technology which allows a computer system to operate even if a memory error occurs.

Why do ECC modules cost more than modules without ECC?

In order to check and correct the memory, additional RAMs are required. A non-ECC module which has eight RAMs would need to have a ninth RAM added; a sixteen RAM module would generally need to have TWO additional RAMs added. Obviously, the additional RAMs make the module more expensive.

So it's kind of like the old parity modules, right?

Well, kind of, but ECC is a WHOLE LOT more useful. The ECC technology used on most x86-architecture PCs and servers is capable of correcting errors, where parity can only detect errors. If you've ever had an error "detected" on your system, you know the result - the blue screen of DEATH! Really useful, huh... With ECC you would sail right through, without crashing or even interrupting normal operation. Much more useful!

Josb
08-12-2003, 06:50 AM
Good topic. I've been under the impression that ECC RAM would be slower, but have never seen any actual apples to apples tests indicating that to be true.

I've also seen comments that ECC is to be used in servers (lots of users) but on a desktop not necessary but with some advocating that if a desktop has "lots" of RAM (like 2gb+) then one is better off with ECC.

Dunno. Have no experience with it, so in way over my head (again).

pointreyes
08-12-2003, 08:52 AM
Originally posted by Josb
Good topic. I've been under the impression that ECC RAM would be slower, but have never seen any actual apples to apples tests indicating that to be true.

It has been slower for me. :( I'm using PC3200 ECC in my Canterwood board. What's really strange is that if I change the memory timings from SPD-my memory scores even get worst. What I really don't understand is that I only took a lost of around 100 points when I first built the system but the last time I checked it's more like 350+ points slower! :cry:

Yes, I'm using this Canterwood somewhat like a server but it also does multi-media.

It has the ATi 9800 Pro and the LeadTek TV2000XP Dlx TV/FM tuner coupled to an Audigy 2 but I'm running Windows 2003 Enterprise Server on it. :rolleyes:

pointreyes
08-12-2003, 09:54 AM
In case anyone is curious about my original results when I changed from PC3500 to PC3200 ECC:
http://www.bleedinedge.com/forum/showthread.php3?postid=1774#post1774

I now cannot reach 2700 at all. :scratch: :beat: :wack: :cry:

Josb
08-12-2003, 01:36 PM
If I'm reading your scores correctly, you didn't drop much going to ECC.

What do you feel you gained by using ECC?

pointreyes
08-12-2003, 01:47 PM
Originally posted by Josb
What do you feel you gained by using ECC?

Accurate memory across the module-no dropping of parity.

mysteryman
08-12-2003, 09:48 PM
on my rdram system, you can selectively turn on/off ecc with
ecc rdram. it will slow you down...