For safety, server and workstation memory often comes with ECC functionality (=Error Correction Code).
The memory controller, known as the Northbridge, must support ECC functionality for this technology to be utilized. Additionally, it is important that all installed memory modules have ECC functionality, as this feature will be disabled when mixed with non-ECC memory.
For every 8 bits of data, an additional 1 bit is carried for parity checking during each memory read and write operation. The “checksum” of the 8-bit data is always logged and checked. The 64-bit wide memory bus is expanded to 72 bits for this purpose. More memory cells are needed, which is why ECC memory can also be identified by the number of DRAMs. Instead of 8, 16, or 32 DRAMs, 9, 18, or 36 DRAMs are required. Using the check bits of an ECC DIMM memory, DataBit errors can be detected and corrected during operation without crashing or causing data loss.
There are unbuffered memory modules (ECC UDIMM) with ECC functionality. ECC functionality is almost always present in registered memory (ECC RDIMM).
How to recognize if a memory module has ECC functionality?
