memory module configurations

memory module configurations

Memory modules are defined by the number of chips they contain. With DIMMs and 72-pin SIMMs, the module designation refers to the number of data words on the module. For example, an 8x32 DIMM means that 8 million 32-bit words of memory are available to the system.

If another number follows the designation, such as 8x32-60, it refers to the speed of the chips, in this case, 60 nanosecond 32MB DIMMs. Sometimes, there is an "M" for "mega" after the first digit; for example, 8Mx32. See memory module for the different memory types. Following are some common memory module configurations:

  168-PIN DIMM
  No parity (8-bits)     Parity (9 bits)
  Config.   Size         Config.    Size
     8x32   32MB            4x72    32MB
     4x64   32MB            8x72    64MB
    16x32   64MB           16x72   128MB
     8x64   64MB           32x72   256MB
    16x64  128MB           64x72   512MB
    32x64  256MB          128x72     1GB
    64x64  512MB
   128x64    1GB


  72-PIN SIMM
  No parity (8 bits)     Parity (9 bits)
  Config.   Size         Config.   Size
     1x32    4MB          256x36    1MB
     2x32    8MB          512x36    2MB
     4x32   16MB            1x36    4MB
     8x32   32MB            2x36    8MB
    16x32   64MB            4x36   16MB
                            8x36   32MB
                           16x36   64MB

  30-PIN SIMM
  No parity (8 bits)     Parity (9 bits)
  Config.   Size         Config.   Size
     1x2     1MB           1x3     1MB
     1x8     1MB           1x9     1MB
     2x8     2MB           2x9     2MB
     4x8     4MB           4x9     4MB
    16x8    16MB          16x9    16MB