ECC ram what exactly does it do?

[bdog]

I have searched some old threads and found out some about it, but still am not clear. I know that it stands for error checking control, but what exactly does this do? Is it worth the extra cost? I have never used it before, so I obviously don't need it, but if it helps in some way I wouldn't mind spending a few extra bucks on it.

[nobs]

ECC (Error Checking and Correcting) performs "double bit detection and single bit correction". This means that if you have a single bit memory error, the chipset and memory will find and repair the error on the fly without you knowing that it happened. If you have a double bit memory error, it will detect and report it. Using ECC decreases your PC's performance by about 2%. Current technology DRAM is very stable and memory errors are rare, so unless you have a need for ECC, you are better served with non-parity SDRAM.
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[This message has been edited by nobs (edited 10-19-2000).]

[Szech]

Hey bdog, it's also bad for overclocking. Anyway, current RAM will have an average of one error per 10 years. Pretty good odds, don't you think? ECC is really only for data critical applications, where even one error per ten years is unacceptable.

[bdog]

Thanks for the information. I think I will stick with the good ole sdram.

[Gene C.]

here is a copy of the post answer I done on another board. concering this same question.

posted 10-11-2000 08:03 AM
I bought ECC memory on a intel al440lx 333, I was told at the time it was the best there was. the only differance I saw was the price and it dose slow down the system somewhat. for it is all the time checking for errors. you can't tell tho.
and as BBA said it will help your system to run better as far as the memory part of it goes. but, most of the time it is used for server systems and that is what I use it for now if the custmer wants to pay the price for it.
and I also might add. if I could put forth the money. I would use it to myself.

here is some more info I had for customes to view on the differance.

Error Correction Code is used primarily in high-end PCs and file servers. The important difference between ECC and parity is that ECC is capable of detecting and correcting 1-bit errors. With ECC, 1-bit error correction usually takes place without the user even knowing an error has occurred. Depending on the type of memory controller your computer uses, ECC can also detect rare 2-, 3-, or 4-bit memory errors. However, while ECC can detect these multiple-bit errors, it can only correct single-bit errors. In the case of a multiple-bit error, the ECC circuit reports a parity error.

Using a special algorithm (mathematical sequence) and working in conjunction with the memory controller, the ECC circuit appends ECC bits to the data bits and together they are stored in memory. When data is requested from memory, the memory controller decodes the ECC bits and determines if one or more of the data bits are corrupted. If there's a single-bit error, the ECC circuit corrects the bit. As mentioned, in the rare case of a multiple-bit error, the ECC circuit reports a parity error.


hope this helps or is what you were looking for

[Gene C.]

here is a copy of the post answer I done on another board. concering this same question.

posted 10-11-2000 08:03 AM
I bought ECC memory on a intel al440lx 333, I was told at the time it was the best there was. the only differance I saw was the price and it dose slow down the system somewhat. for it is all the time checking for errors. you can't tell tho.
and as BBA said it will help your system to run better as far as the memory part of it goes. but, most of the time it is used for server systems and that is what I use it for now if the custmer wants to pay the price for it.
and I also might add. if I could put forth the money. I would use it to myself.

here is some more info I had for customes to view on the differance.

Error Correction Code is used primarily in high-end PCs and file servers. The important difference between ECC and parity is that ECC is capable of detecting and correcting 1-bit errors. With ECC, 1-bit error correction usually takes place without the user even knowing an error has occurred. Depending on the type of memory controller your computer uses, ECC can also detect rare 2-, 3-, or 4-bit memory errors. However, while ECC can detect these multiple-bit errors, it can only correct single-bit errors. In the case of a multiple-bit error, the ECC circuit reports a parity error.

Using a special algorithm (mathematical sequence) and working in conjunction with the memory controller, the ECC circuit appends ECC bits to the data bits and together they are stored in memory. When data is requested from memory, the memory controller decodes the ECC bits and determines if one or more of the data bits are corrupted. If there's a single-bit error, the ECC circuit corrects the bit. As mentioned, in the rare case of a multiple-bit error, the ECC circuit reports a parity error.


hope this helps or is what you were looking for