SIMMs taking up all the memory banks Figure 2. SIMMs installed in the memory banks SIMM connectors can be either tin plated or gold. One DIMM is basically equivalent to a pair of SIMMs but uses less space. Like SIMMs, most DIMMs install vertically into expansion sockets. Many PCs require SIMMs that are capable of parity checking.
Parity requires that an extra bit be sent at the end of each byte of data to hold the parity value.
This parity bit is used to ensure that your information is being sent properly. Check the manual of your computer to see what type of memory chips are installed on your motherboard. If your manual doesn't let you know if you have parity memory, an easy way to determine it is to count the number of chips on the 1 or 4MB SIMMs already in your system. If they have two or eight chips on them, you don't need parity. If they have three, nine, or twelve, you do.