EEC, non ECC, registered DDR RAM
can anyone explain what is the difference (if any) between EEC, non EEC, registered DDR RAM. Is there anyway to check what type I have. I am afraid I might have bought something that is incompatible with my MB.
All these years, I've been directing people to Crucial's FAQ - good source of info!
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Error Correction Code is the data integrity checking method 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 the computer uses, ECC can also detect rare 2-, 3- or 4-bit memory errors. While ECC can detect these multiple-bit errors, it cannot correct them. However, there are some more complex forms of ECC that can correct multiple bit errors. Using a special mathematical sequence, algorithm, and working in conjunction with the memory controller, the ECC circuit appends ECC bits to the data bits, which are stored together in memory. When the CPU requests data 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. In the rare case of a multiple-bit error, the ECC circuit reports a parity error.
A registered module is SDRAM/DDR memory that contains registers directly on the module. The registers
re-drive the signals through the memory chips and allow the module to be built with more memory chips. Registered and unbuffered memory cannot be mixed. The design of the computer memory controller dictates which type of memory the computer requires.