The 168 pin DIMM may be identified by two notches.
The leftmost notch identifies if the chip is registered (RFU), Buffered, or un-buffered.
The notch near the center identifies the voltage. (3.3 or 5.0 volts)
The 168 pin DIMM has a 64 bit data path, therefore only 1 module is required per bank. DIMMs are inserted into the slot vertically. At each end of the module on the slot there is a wing like attachment that may be used to assist in inserting and removing the module.
