Good, bad, better than SDRAM or DDR?

I don't know. Not familiar with this type of RAM. Is it a 'feature' of SDRAM/DDR or something totally different? I was able to dig up some info:
ECC has the ability to correct a detected single-bit error in a 64-bit block of memory. When this happens, the computer will continue without a hiccup; it will have no idea that anything even happened. However, if you have a corrected error, it is useful to know this; a pattern of errors can indicate a hardware problem that needs to be addressed. Chipsets allowing ECC normally include a way to report corrected errors to the operating system, but it is up to the operating system to support this. Windows NT and Linux do detect these messages, but Windows 95 does not. In the latter case, you will not know when ECC has corrected a single-bit error. The user must decide if this is a concern or not; setting the system for simple parity checking will cause notification when an error occurs, but on-the-fly correction will be lost.

ECC will detect (but not correct) errors of 2, 3 or even 4 bits, in addition to detecting (and correcting) single-bit errors. ECC memory handles these multi-bit errors similarly to how parity handles single-bit errors: a non-maskable interrupt (NMI) that instructs the system to shut down to avoid data corruption. Multi-bit errors are extremely rare in memory.

Unlike parity checking, ECC will cause a slight slowdown in system operation. The reason is that the ECC algorithm is more complicated, and a bit of time must be allowed for ECC to correct any detected errors. The penalty is usually one extra wait state per memory read. This translates in most cases to a real world decrease in performance of approximately 2-3%.
Which leads me to believe there is some type of program (provided through the MB/OS) that would be helpful in monitoring hardware -- but what type; MB, hard drive, the RAM itself, all hardware?

Is the, "real world decrease in performance of approximately 2-3%", worth it?

Can anyone enlighten me on this subject?

ECC comes with SDRAM and DDR. Meaning you can get it in both types.

It's a bit more costly, but I'd put it in my servers.

I have 1.5GB Mushkin Registered/ECC DDR PC2100 in my home computer and ECC SDRAM in our servers. Only reason why I have it in my home computer is because my board requires Registered chips if I use over 2 slots.

well, for high end servers I suggest using ECC memory... have you heard about IBM's technology that is even better than ECC?:)

Yes ECC is always the choice for servers, thats unless you really do not have the money to spare. Then, the next step is to look for quality chips. Kingston and some others make good ones.

The ones at Costco or some little dinky computer shop are not trustable for servers as they might be lower end, lower quality ram which did not meet standards and ended up in the market for home users.

Pretty much summing it all up, not all ram are created equal.

Appriciate the info and was wondering if anyone has used or has comments, on the "supposed" ability of, "Chipsets allowing ECC normally include a way to report corrected errors to the operating system", and if the slowdown is at all noticeable?

Haven't heard anything about IBM technology for RAM memory and as for Kingston Memory, I used to buy it until I found out it was actual a Micron product repackaged with their name. Now I only buy Micron RAM and without having to pay for the Kingston name, it's a lot less expensive. Sort of like, if you buy a Sony "anything", you know you are paying extra because of the name -- a somewhat bad example since only Sony makes a Sony, but you get the idea.

Originally posted by Website Rob
Sort of like, if you buy a Sony "anything", you know you are paying extra because of the name -- a somewhat bad example since only Sony makes a Sony, but you get the idea.

Don't know how this applies to the situation at hand, but sometimes paying for the name brand also means you get better support and some sort of quality guarantee ;)