When adding new memory, you need to match what is already in your
system. Parity modules have an extra chip that detects if data was
correctly read or written by the memory module, depending on the type
of error. However, a parity module will not correct the error.
can determine if your system has parity by simply counting the number
of black memory chips on each module. Parity (and ECC) memory modules
have a chip count divisible by three or five. Any chip count not
divisible by three or five indicates a non-parity memory module.