Network cards and network controllers are expansion boards inserted into computers that allow them to connect to a network. They are also known as network interface cards (NIC) or network adapters. Network protocol, configuration, processor specifications, memory, general features and options, and environmental parameters are all important specifications to consider when searching for network cards and network controllers. Common features for network cards and network controllers include direct memory access (DMA), military standard, and plug and play. An important environmental parameter to consider when searching for network cards and network controllers includes the operating temperature.
Network protocol is an important specification to consider when selecting network cards and network controllers. Choices for network protocol include ATM, CANbus, ControlNet, DeviceNet, ARCNET, 10 Base-T Ethernet,10 Base-2 Ethernet, Fast Ethernet, gigabit Ethernet, FDDI, Fibre Channel, Fieldbus, INTERBUS, parallel, PROFIBUS, serial, and Token Ring. Wireless network cards and network controllers can be used in wireless systems. The data rate, the speed at which data is transferred, is also an important specification for network cards and network controllers.
Important configuration specifications to consider when selecting network cards and network controllers include host bus, number of ports, port type, and operating systems. Choices for host bus include GPIB, IDE or ATA, ISA or EISA, MCA, NuBus, PC/104, PCMCIA, PCI, PXI, Sbus, SCSI, VME or VXI, CompactPCI, PMC, and PC*MIP. The number of ports refers to the number of available ports for interfacing to the device. Port types include BNC, IEEE 1394, parallel, RJ-45, RS232, RS422, RS485, and USB. Common operating systems for network cards and network controllers include Windows® 9X, MS-DOS, Windows NT®, Windows® 2000, Mac OS, NetWare, OS/2, Linux, SUN Solaris, and SCO UNIX (x86).
Processor specifications and memory refer to network cards and network controllers which have an onboard CPU. The CPU speed refers to the speed at which the CPU operates internally. It is calculated by multiplying the memory bus speed by the multiplier of the processor, or Processor Speed = Memory Speed x Multiplier. The multiplier is different for each processor. For instance, for a Pentium II 350 the multiplier is 3.5, and for a Pentium II 450 the multiplier is 4.5. RAM and cache memory (L1 and L2) are important CPU specifications to consider. RAM (Random Access Memory) is the main memory of the computer. The cache contains the data that is accessed most often between the CPU and memory. Cache memory accounts for a small amount of high-speed RAM and is the memory that the processor most often utilizes. With network cards and network controllers, the cache runs almost as fast as the processor.