Glossary of Acronyms

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NIC - Network Interface Card.  An expansion card or other device used to connect a computer to a local area network (LAN). Also called a network adapter or network adapter card.

NSEC - Nanosecond. A billionth of a second. The length of time between clock cycles are measured in nsec. The speed of DRAM is measured in nsec.

NTSC - The National Television Standards Committee. Governs the standard for television and video playback and recording in the United States. The NTSC was originally organized in 1941 when TV broadcasting first became prevalent. The original standard they created was called RS- I 70A, which is now simply referred to as NTSC. The NTSC standard provides for 52S scan lines of resolution and is transmitted at 60 half-frames per second. It is an interlaced signal, which means that it scans every other line each time the screen is refreshed. The signal is generated as a composite of red, green, and blue signals for color and includes an FM frequency for audio and a signal for stereo. Twenty years later, higher standards were adopted in Europe with the PAL and SECAM systems, both incompatible with the NTSC standard of North America. NTSC is also called composite video.

NUMA - Non-Uniform Memory Process Access. A system built from a collection of metanodes, each of which consists of one or more processors in a standard SMP (Symmetric Multiprocessing) configuration. Each processor has its own cache, and is connected to I/O and memory via a high speed, cache coherent bus. Sophisticated high speed hardware manages local memory accesses to memory on the local processor bus, and remote memory accesses to the memory on the other metanodes. NUMA also uses techniques such as hierarchical memories and intelligent resources management to optimize processor workloads and maintain its single memory personality.

A typical NUMA system consists of multiple four processor motherboards. Currently, DG's NUMALine of systems can support up to 256 processor boards, significantly more than the 16 board SMP systems that are widely available. These boards are coupled by standardized interconnect technology that implements NUMA across the full SMP system. Each motherboard contains four Intel Pentium processors, with up to 512K of cache per processor and 4GB of memory per node, and dual PCI I/O channels. In this architecture, the cache memory (the L2 cache) runs at processor speed and is accessible with each processor cycle. Requested data that is not in the cache is read from the main memory and copied into the L2 cache.

In a typical NUMA system, if requested data is not in cache or in near main memory, it must be retrieved from far memory, residing on another node, via the interconnect bridge. The role of the interconnect bridge is crucial to preserving the high speed of the processors. Based on standard scaleable coherent interface (SCI) technology, it forms a fast 1 GB/sec point to point link between nodes. It contains operating system interfaces and maintains a larger level L3 cache that works with SCI logic to enforce cache coherence across the entire weave of interconnected motherboards.

NVRAM - Nonvolatile Memory Random-access memory whose data is retained when power is turned off. Sometimes nonvolatile RAM is retained without any power whatsoever, as in EEPROM or flash memory devices. In other cases the memory is maintained by a small battery. Nonvolatile RAM that is battery maintained is sometimes also called CMOS memory. CMOS NVRAM is used in IBM-compatible systems to store configuration information. True NVRAM often is used in intelligent modems to store a user-defined default configuration loaded into normal modem RAM at power-up. Memory which can be modified like normal RAM but does not lose its contents when the system's power is turned off. This memory may be powered by a battery when the system power if off, or it may be a type of memory which does not need electricity to maintain its contents, such as EEPROM or bubble memory.

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Compiled by Scott McArdle, MagnaCom Limited. I hope this list has helped you and if there is an item that should be on this list, please let me know. Thanks. PS, I've spent 100's of hours maintaining this list, please don't be a LAMER.