PNY OPTIMA 2GB (2x1GB) Dual Channel Kit DDR 400 MHz PC3200 Desktop DIMM Memory Modules MD2048KD1-400

2GB Kit (2x1GB) PC3200 400MHz DDR Desktop DIMMs , notebook computers and processors such as Intel¿s Pentium, Celeron, AMD¿s Athlon, Sempron and others. PNY upgrade modules are compatible with systems from Apple, Compaq, DELL, Gateway, HP, IBM and over 5000 other systems. Boost the performance of your PC to its maximum capability. PNY memory upgrades will prove to be an outstanding value both now and in the future.

Crucial CT2KIT25664BC1067 4GB 204-PIN PC3-8500 SODIMM DDR3 Memory KIT (2GBx2)

In short, 204-pin small outline dual inline memory modules (SODIMMs) are the form factor used to provide DDR3 memory modules for notebook computers and other small form factor computing platforms. 204-pin SODIMMs are currently available in PC3-8500 (DDR3 1066MHz) speeds.

To use DDR3 memory, your system must have both a 204-pin SODIMM slot and a chipset that supports DDR3 memory. A DDR3 SODIMM will not fit into DDR2 or DDR memory sockets. (Information about which memory technology your system uses is included in the Crucial Memory Advisor tool.) SODIMMs are smaller and thinner than regular DIMMs, and the 204-pin SODIMM PCBs are always ~2.6 inches long and are usually around 1.75 inches high (though the heights can vary slightly).

They consist of a number of memory components (usually black) that are attached to a printed circuit board (usually green). The number of memory components on a 204-pin SODIMM's printed circuit board (PCB) can vary, but the PCB will always have 102 pins on the front and the back both, for a total of 204 pins. The gold pins on the bottom of the SODIMM provide the connection between the memory module and the memory socket.