What kind of memory is this?

Most of the memory we are run into at Free Geek, falls into one of two categories (DIMM and SIMM):

DIMM

Dual Inline Memory Modules are newer and longer than the older SIMMs (see below). All DIMMs are the same length, and they can be distinguished by the number and positions of their notches.

SDRAM

A stick of SDRAM has two notches in it, one near the center of the stick, and one closer to the side.

DDR

A stick of DDR has a single notch in it near the center of the stick.

DDR2

A stick of DDR2 resembles DDR. The single notch is in a different position, and if there is a label, it will often include the letters "PC2".

DDR3

A stick of DDR3 resembles DDR. The single notch is in a different position, and if there is a label, it will often include the letters "PC3".

RAMBUS

A stick of RAMBUS has two notches in it at the center of the stick.

SIMM

Single Inline Memory Modules are older and shorter than the DIMMs. There are two varities, 30 pin SIMMs and 72 pin SIMMs. Both are substantially shorter than the DIMMs (above). We normally do not want to keep SIMMs these days.