Notebook Memory

Notebooks use memory modules called SODIMM'S which are available in the same speeds as regular memory such as PC100, PC133, PC2100 (DDR266), PC2700 (DDR333).

SODIMM's are shorter than regular memory sticks due to space restrictions. The notch or key along the pin edge is the easiest way to distinguish if a stick is DDR or not (if the sticker or label happens to be missing).

144 pin PC133 SODIMM	200 pin DDR PC2100 SODIMM

DDR is used in nearly all new or current notebook computers that use Pentium M, Pentium 4, Athlon 64, Athlon XP-M, etc (see processor section) and Non-DDR is used on older notebooks that use processors such as the Pentium 2 or 3, etc.

Buying or Upgrading Notebook Memory

If you're configuring a new notebook check to see how much the manufacturer charges for a single stick of 512 MB and compare to 3rd party prices, in many cases you can save a lot of money by selecting the minimum memory configuration and upgrading it using memory bought elsewhere. You can have more total memory for less than the cost of the manufacturers single 512 MB option. Same goes for other memory amounts but 1 gig sticks are terribly expensive still.

If the minimum memory configuration is 256 MB try to make sure it's a single stick of 256 MB rather than two sticks of 128 MB. Notebooks only have two memory slots so when you decide to add another 512 MB you would have 768 MB total instead of removing 128 MB to accommodate the upgrade and ending up with only 640 MB.