Notebook Memory FAQ’s

A notebook's hard drive is its long-term memory, and RAM is short-term (temporary) memory. In addition to RAM and hard drive memory, there is also "Level 1" or primary cache. This is faster and more efficient than RAM with a microprocessor.

A laptop uses notebook memory modules called SODIMMs (small outline dual inline memory modules). These are available in the same speeds as conventional memory. Notebook memory modules are shorter than regular memory sticks due to space restrictions.

DDR (double data rate) memory is used in almost all new or current notebook computers that run on Pentium M, Pentium 4, Athlon 64, or Athlon XP-M, while non-DDR notebook memory is used on older, outdated laptops that run on processors such as the Pentium 2 or 3. It's easy to tell whether the memory is DDR or non-DDR from the notch or key along the pin edge.