Computer Cores
Computer cores are the very heart of a starship's computer system. They provide enormous amounts of memory and faster-than-light data processing.

The computer network of a starship is based around a system of redundant computer cores that process data for all the ship's systems. Every single system, from life support to weapons arrays and shielding, depends on the computer cores. A Galaxy-class ship is equipped with three main processing cores, any one of which can, in an emergency, handle the operational computing load of the the entire vessel.

On the USS Enterprise NCC-1701-D, two primary cores were located across decks 5 and 14 of the saucer section; these usually worked in sync and if one failed the other could immediately take on its load, with little or no disruption to the ship's operations. The third computer core crossed decks 30 to 37 in the engineering hull; it was a backup core and was normally only used if a problem arose in the saucer section or when the ship was separated. Each core incorporated a series of miniature subspace field generators, which allowed data to be processed and transmitted at fast-than-light (FTL) speeds. In a Galaxy-class starship, the computer cores are massive, cylindrical structures. The top level of each primary core, located on deck 5, incorporates a systems monitoring room, the FTL nanoprocessor units, and access to the subspace field systems, which are located in a separate cylindrical structure to the side of the main core. This section is known as the upper core; beneath this are six levels of the lower core.

The cores are connected to the Optical Data Network (ODN) by a series of Micron Junction Links (MJL). They are supported by a network of 380 optical subprocessors, all of which are linked to the ODN, and many of which are directly linked to the cores. Virtually every sensor, console, replicator, PADD, and miscellaneous piece of hardware installed on a starship is in some way connected to the optical data network and uses the computer cores for data processing. Backups, engineered redundancies, and automatic service reductions are built into the system to guarantee that basic available in all but the most grave situations. Pipelines for two additional ODN systems, located elesewhere in the ship, back up the primary lines. These lines, between vital terminals and important systems, are also shielded, and if all else fails the radio frequency (RF) system, through which the communicators run, can also act as an ODN, albeit at a considerable loss of speed.