HP Deskpro 4000 Appendix page 15

To identify the SDRAM data width, use the total memory of the DIMM Module, the total
number of SDRAM chips and the information Table E-1. By knowing the total size of the DIMM
Module and how many SDRAM chips are on each side of the module, the memory technology
and data width of the SDRAM chips can be determined.
For example, a 32 MB DIMM Module with 8 chips on each side for 16 chips total is most likely
comprised of 16Mb technology SDRAM chips with a data width of x8.
That same 32 MB DIMM Module, but with only 4 chips on one side is most likely comprised of
64Mb technology SDRAM chips with a data width of x16.
E-2 Dual Inline Memory Module Configurations