GLOSSARY
|
Access Time |
A measurement of time in nanoseconds (ns) used to indicate the speed of memory. Access time is a cycle that begins the moment the CPU sends a request to memory and ends the moment the CPU receives the data it requested. Memory modules complete this process in as fast as 6ns for PC133mhz memory while older modules can take up to 80ns or more. |
CMOS
|
Complementary Metal Oxide Semiconductor: a process that uses both N- and P-channel devices in a complimentary fashion to achieve small geometries and low power consumption |
DRAM |
(Dynamic Random Access Memory) DRAM is the most common type of memory and is "dynamic" because in order for the memory chip to retain data, it must be refreshed constantly (every few milliseconds). If the cell is not refreshed, the data is lost. DRAM temporarily stores data in a cell composed of a capacitor and a transistor. Each cell contains a specified number of bits. These cells are accessed by row addresses and column addresses. |
EEPROM |
Electrically Erasable, PROgrammable, Read-Only Memory chip. EEPROMs differ from DRAMs in that the memory stays in even if electrical power is lost. Also, the memory can be erased and reprogrammed. |
cache |
Sometimes also known as primary or level 1 cache, is a small amount of high-speed memory that resides on or very close to the CPU. L1 Cache interacts with the CPU for most frequently requested instructions and data. |
Bus |
The central communication avenue in a PCs system board. It normally consists of a set of parallel wires or signal traces that connect the CPU, the memory, all input/output devices, and peripherals and allows data to be transferred from one system component to another. Busses come in a variety of bit widths and speeds. To prevent data bottlenecks, the components attached to a bus must operate at close to the same speed as the bus. |
| CPU | (Central Processing Unit)--The chip in a computer that has primary responsibility for interpreting commands and running programs. The CPU is the most vital component of a computer system. The speed of the CPU has a significant impact on overall system performance, but the CPU doesn't act alone. If slower memory is paired with a fast processor, the processor will be forced to wait for the memory to respond. When the speed mismatch is extreme, the user will see numerous memory errors and even complete system failure. |
| Kilobit | Approximately one thousand bits: 1 bit x 210 (that is, 1,024 bits). |