How can I tell if a memory module is ECC parity RAM or non-ECC non-parity RAM?

Parity memory modules have an extra chip on them to check for errors. Therefore, non-parity memory should have an even number of chips on the module and parity memory should have an odd number. Typically, there will be 8 chips on a non-ECC module and 9 chips on an ECC module.

However, some parity SIMMs can have 12, 18, 24 or 36 chips. Therefore, a sure-fire way to determine of a memory module is parity or non-parity is to divide the number of chips on the module by three. If the number is evenly divisible by 3, it is a parity, or ECC module. If the number of chips is not divisible by three, the module is non-parity, or non-ECC.