Can I replace non-ECC memory with ECC memory?

Answer: ECC (Error Correcting Code) memory is parity memory and non-ECC memory is non-parity. Parity memory has an extra chip on the module that checks for errors in the transfer of information to and from the memory. So if a memory module has an odd number of chips, it is parity RAM.

Many motherboards support both ECC and non-ECC memory. Some sources say you can even mix the two types of RAM and the ECC RAM will work as non-ECC memory. However, most memory companies do not support mixing the two types, so try it at your own risk. Since most motherboards will accept ECC memory, it often depends on if your computer's BIOS supports it. You may have to check your computer's manual to find the answer.

If you have a choice, non-ECC memory is typically cheaper than ECC memory and works slightly faster. So when in doubt, use non-ECC memory.

Published: April 28, 2005 — by Per Christensson