> IBM Memory > IBM ThinkPad Laptop Memory
Memory Upgrade for IBM ThinkPad A21e 2655-2xx/7xx
IBM ThinkPad A21e 2655-2xx/7xx memory upgrade specification, ThinkPad A21e 2655-2xx/7xx maximum memory, memory speed, and memory upgrade options.
Upgrade memory on IBM ThinkPad A21e 2655-2xx/7xx upto a maximum of 256 MB
PC100 SDRAM SODIMMs, with maximum 128MB per slot in 2 memory slots. The IBM ThinkPad A21e 2655-2xx/7xx takes the PC100 SDRAM SODIMMs Memory Type.
| IBM ThinkPad A21e 2655-2xx/7xx Memory Upgrade Specification | ||||
|---|---|---|---|---|
| Standard Memory | Maximum Memory | Memory Expansion | CPU Type | Model/Chipset |
| 64 MB (removable) | 256 MB PC100 SDRAM SODIMMs |
2 sockets | 650MHz Intel Mobile Celeron | 100MHz FSB, Intel 440MX Chipset |
IBM ThinkPad A21e 2655-2xx/7xx Memory Upgrade options.
What are memory sockets or slots and how are these divided into bank?
Memory Sockets or Slots are the place where memory RAM modules are inserted in the motherboard. The IBM ThinkPad A21e 2655-2xx/7xx has 2 memory expansion slots. A memory bank is a group of memory expansion sockets, a bank must be completely filled with memory modules of the same size and type in order for the system to recognize and address the memory. i.e. :
2 sockets (2 banks of 1) This indicates that there are 2 memory slots. These are divided into 2 banks, and each bank consists of one memory slot. So you can add memory one piece at a time for the system to use.
3 sockets (3 banks of 1) This indicates that there are 3 memory slots. These are divided into 3 banks, and each bank consists of one memory slot. So you can add memory one piece at a time for the system to use.
4 sockets (2 banks of 2) This indicates that there are 4 memory slots. These are divided into 2 banks, and each bank consists of two memory slots. So you must add memory two pieces at a time (they must be the same size and type of memory) in order for the system to benefit from the upgrade.
8 sockets (4 banks of 2) This indicates that there are 8 memory slots. These are divided into 4 banks, and each bank consists of two memory slots. So you must add memory two pieces at a time (they must be the same size and type of memory) in order for the system to benefit from the upgrade.
12 sockets (3 banks of 4) This indicates that there are 12 memory slots. These are divided into 3 banks, and each bank consists of four memory slots. So you must add memory four pieces at a time (and they must be the same size and type of memory) in order for the system to benefit from the upgrade.
