Re: ECC has 2 Flavors

Registered means that there is a register chip with a PLL on the DIMM. This means that the register is an address buffer which outputs the addresses to the chips on the next clock cycle so you have one cycle addtional access latency.

ECC means that for 64 bit data there are 8 bits of checksum. The data from the memory are read twice, the bit-checksum is then forwarded to the ECC chip and then the cycle is repeated. If there is a difference in the checksum, the correct data are output to the bus.

Then there are buffered DIMMs which hold the data in a data buffer and release them on the same clock cycle but either amplified or with a new chipset address arbitration (like in the case of some of the older Abit boards) to override the chipset limitation of memory. This happens on the same clock cycle which is why buffered is used only on slow interfaces because otherwise things will get really sluggish.

Thus, buffered, registered and ECC are three terms that really have nothing to do in the strict sense of the word but all three technologies are often used in combintation with each other.

Thus, buffered, registered