Registered and ECC RAM?

[rivercom9]

What are the diffs between registered RAM and ECC RAM?

[DJL]

ECC stands for Error Checking and Correcting.
Basically this allows the computer to check if data has been read/written to RAM correctly, and if not it can correct the data. The process can slow down the computer very slighly.

Registered RAM contain a register that delays all information transferred to the module by one clock cycle. This helps insures that the system handles the data properly. It also reduces that electrical load on the Memory Controller.

You can get ECC RAM that is registered.

For gaming you want neither of the above as they can both decrease system performance, but they both increase stability and are usally used in mission critical servers and workstations.

Daniel

[rivercom9]

What about buffered RAM? Is it the same as ECC?

[Jon]

No.

Buffered means adding logic, particularly drivers, to a SIMM or DIMM to increase the output current. Buffering is used to overcome signal attenuation due to capacitive loading. Modules that are "buffered" usually have small buffer chips mounted on them.
ECC is similar to parity, however, where parity can only detect errors, ECC can actually correct most errors. ECC memory uses extra bits to store an encrypted code with the data. When the data is written to memory, the ECC code is simultaneously stored. Upon being read back, the stored ECC code is compared to the ECC code generated when the data was read. If the codes don't match, they are decrypted to determine which bit in the data is incorrect. The erroneous bit is "flipped" and the memory controller releases the corrected data.

[Mojoman]

Cool.