what's ECC?

Question

what's ECC when they say 'no ECC' on memory stick for computers? And what does it do?

Answer 1

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.

I don't understand why these memory errors occur. What gives?
- Unfortunately, the Ram Guy is not a physicist. But, he did speak to one, and was told that there are two main causes of these errors:

naturally occurring radioactive isotopes (which emit alpha particles), and
high energy cosmic rays from supernovas
Both of these phenomena can change the value of a memory bit from a zero to a one or from a one to a zero.

By the way, these errors are known as "soft" errors. They are called "soft" because they can be repaired by simply correcting the value of the memory bit.

What's the bottom line?
- If you are running any kind of server, we think you are NUTS if you don't use ECC. For desktops with 256MB or less of memory that are running typical office applications, ECC is really not necessary. For high performance workstations or other systems with more than 256MB of memory, the Ram Guy would recommend that you use ECC, but will cut you some slack if you feel differently

Answer 2

I've heard a couple of different takes on the ECC acronym over the years: Error Checking and Correction and Error-Correcting Code memory. Whatever you choose to call it, ECC memory includes special circuitry for testing the accuracy of data as it passes in and out of memory. One common misconception is that if a stick of memory is capable of ECC it must also be registered (this is certainly a common combination). This is incorrect as you can find unbuffered, ECC modules if you look hard enough.

As a general rule, a quick way to find out if a stick of memory is capable of ECC is to count the number of DRAM chips on the module. If you look closely at the pictures above, you'll note that the unbuffered stick has 8 separate DRAM chips on the module while the registered/ECC part has 9. It's the 9th chip that allows for the 8-bits of error checking and correction, if needed.

Answer 3

ECC is acronym for Error Checking and Correction or Error Correction Code, no difference. If a memory is equipped with ECC, it is capable of some error checking and correction, so the prabability of losing data during transmission is reduced.

Answer 4

Error correcting code. Logic designed to detect and correct memory errors.