Single-sided / double-sided

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The terms single-sided ( SS ) and double-sided ( DS ) are used in digital storage technology and have different meanings depending on the medium.

Storage media

Memory modules

In the case of memory modules , the terms single-sided and double-sided indicate whether the modules are equipped with memory chips on one or both sides of the circuit board. While in some series (e.g. SIMM ), conclusions could also be drawn from this about the electrical connection, i.e. the organization of the module, this is generally not the case. Therefore were names for the organization for better differentiation as single-rowed / double-rowed , row / double row  , single-banked / double-banked , single-ranked / double (dual) -ranked   etc. introduced.

The following rule of thumb applies to distinguish between SDRAM modules:

  • If chips are soldered on only one side of the module, it is practically always a one-bank module.
  • If eight or more chips are soldered on each side of the module, it is very likely that it is a two-bank module.
  • If four or fewer chips are soldered on each side of the module, the organization cannot be seen. In this configuration, one- and two-bank modules occur equally.

When equipping the main board with main memory, attention should be paid to the number of banks per memory module, because a main board can only manage a certain number of memory banks. One-bank modules are normally supported by every memory interface. Two-bank modules, on the other hand, must be explicitly supported by the memory interface on the motherboard, which is not always the case with current products. If the motherboard does not support two-bank modules or does not have enough memory banks free, half the capacity of the module is usually recognized and managed.


In the field of disk storage media, such as floppy disks or hard disks , it is described whether the media contain information on one or both sides. In the past, these media only contained data on one side, today almost exclusively on both.


DVDs are available as single-sided and double-sided versions (not to be confused with single-layer and double-layer). Double-sided DVDs have twice the capacity of single-sided DVDs, but they can only be used with the disadvantage of reinserting the medium.

Web links

Individual evidence

  1. Thorsten Leemhuis, Jörg Wirtgen: Mainboards with DDR memory interface for AMD processors. ( Memento of January 3, 2002 in the Internet Archive ) c't 1/2002, p. 130.
  2. Memory ranks and Intel E7320 / E7520 chipset based servers ( Memento of the original from March 31, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF, 278 kB). Kingston Technology memory ranking technical brief, April 2005. @1@ 2Template: Webachiv / IABot /