(^154) PC Hardware: A Beginner’s Guide
its edges and avoid touching the components on the board. The SIMM should click into
place and stand vertically in the socket.
Installing a DIMM on a PC
Compared to a SIMM, a DIMM module presents a few additional challenges and choices.
First, a DIMM is installed straight down into its socket on the motherboard. The module
has alignment notches like a SIMM, but it is inserted vertically into its socket and pressed
into place. The DIMM mounting socket has locking tabs that should snap into place when
the module is correctly installed, as shown in Figure 7-11.
All DIMMs have 168 pins, with the exception of the SODIMM used inside portable
computers. So that worry is removed, but a DIMM has a few other options that must be
matched to your system: Voltage DIMMs are available with 3.3v or 5v to match the voltage used on
a motherboard.
Buffering DIMM modules are available either as buffered or nonbuffered.
Buffering adds a small amount of logic to a DIMM to increase its output flow.
For a glossary of memory terms, visitwww.memory.com/glossary.html.
Notching DIMM modules have different alignment notches based on the
combination of its voltage and buffering options. So, if a DIMM module will
not fit into the socket on your motherboard, it is likely the wrong type and
combination for your PC.Figure 7-11. A DIMM module installed on a motherboard