# What is DIMM depth/width?

### In case of the DIMM1 above, what's the values of DIMM depth and width?

Depth = 16 (The Memory Depth is the total memory capacity in bits divided by the non-parity memory width, ie 1024 / 64)

Width = 64 (The Memory Width specifies the data width of the memory module interface in bits. )

### What is DIMM depth/width?

Memory Geometry Notation

Various methods of specifying memory geometry can be encountered, giving different types of information.

Module

(Memory Depth) x (Memory Width)

The Memory Width specifies the data width of the memory module interface in bits. For example, 64 would indicate a 64-bit data width, as is found on non-ECC DIMMs common in SDR and DDR1-4 families of RAM. A memory of width of 72 would indicate an ECC module, with 8 extra bits in the data width for the error correcting code syndrome. (The ECC syndrome allows for single bit errors to be corrected). The Memory Depth is the total memory capacity in bits divided by the non-parity memory width. Sometimes the memory depth is indicated in units of Meg (220), as in 32×64 or 64×64, indicating 32 Mi depth and 64 Mi depth, respectively.

Chip

(Memory Density)

This is the total memory capacity of the chip. Example: 128 Mib.

(Memory Depth) × (Memory Width)

Memory Depth is the Memory Density divided by Memory Width. Example: for a memory chip with 128 Mib capacity and 8 bit wide data bus, it can be specified as: 16 Meg × 8. Sometimes the "Mi" is dropped, as in 16×8.

(Memory Depth per bank) × (Memory Width) × (Number of Banks)

Example: a chip with the same capacity and memory width as above but constructed with 4 banks would be specified as 4 Mi x 8 x 4.

Source Memory geometry - Wikipedia