Definition of Cache

cache
<memory management> /kash/ A small fast memory holding recently accessed data, designed to speed up subsequent access to the same data. Most often applied to processor-memory access but also used for a local copy of data accessible over a network etc.
When data is read from, or written to, main memory a copy is also saved in the cache, along with the associated main memory address. The cache monitors addresses of subsequent reads to see if the required data is already in the cache. If it is (a cache hit) then it is returned immediately and the main memory read is aborted (or not started). If the data is not cached (a cache miss) then it is fetched from main memory and also saved in the cache.
The cache is built from faster memory chips than main memory so a cache hit takes much less time to complete than a normal memory access. The cache may be located on the same integrated circuit as the CPU, in order to further reduce the access time. In this case it is often known as primary cache since there may be a larger, slower secondary cache outside the CPU chip.
The most important characteristic of a cache is its hit rate - the fraction of all memory accesses which are satisfied from the cache. This in turn depends on the cache design but mostly on its size relative to the main memory. The size is limited by the cost of fast memory chips.
The hit rate also depends on the access pattern of the particular program being run (the sequence of addresses being read and written). Caches rely on two properties of the access patterns of most programs: temporal locality - if something is accessed once, it is likely to be accessed again soon, and spatial locality - if one memory location is accessed then nearby memory locations are also likely to be accessed. In order to exploit spatial locality, caches often operate on several words at a time, a "cache line" or "cache block". Main memory reads and writes are whole cache lines.
When the processor wants to write to main memory, the data is first written to the cache on the assumption that the processor will probably read it again soon. Various different policies are used. In a write-through cache, data is written to main memory at the same time as it is cached. In a write-back cache it is only written to main memory when it is forced out of the cache.
If all accesses were writes then, with a write-through policy, every write to the cache would necessitate a main memory write, thus slowing the system down to main memory speed. However, statistically, most accesses are reads and most of these will be satisfied from the cache. Write-through is simpler than write-back because an entry that is to be replaced can just be overwritten in the cache as it will already have been copied to main memory whereas write-back requires the cache to initiate a main memory write of the flushed entry followed (for a processor read) by a main memory read. However, write-back is more efficient because an entry may be written many times in the cache without a main memory access.
When the cache is full and it is desired to cache another line of data then a cache entry is selected to be written back to main memory or "flushed". The new line is then put in its place. Which entry is chosen to be flushed is determined by a "replacement algorithm".
Some processors have separate instruction and data caches. Both can be active at the same time, allowing an instruction fetch to overlap with a data read or write. This separation also avoids the possibility of bad cache conflict between say the instructions in a loop and some data in an array which is accessed by that loop.
See also direct mapped cache, fully associative cache, sector mapping, set associative cache.
(1997-06-25)

cache
cache

A special memory subsystem in which frequently used data values are duplicated for quick access. A memory cache stores the contents of frequently accessed RAM locations and the addresses where these data items are stored.

Cache
A Cache Memory is a small but very fast memory used to store frequently used Data or instructions. It tries to "guess" what data is going to be needed next by the Processor . The Cache can be:-
 Level 1 (Primary) Cache - part of the processor itself - fast expensive
 Level 2 (Secondary) Cache - Mounted on the Motherboard slower than Level 1

Cache
Area of your computer memory or directory on your hard disk. This is the place where your browser stores viewed Web pages . When you return to a page, the browser gets this page from the cache, saving you time. However, if you return to a page that changes a lot, you need to click the "Reload" button on your browser to get the latest version.

Cache
A storage area in both RAM (cache memory) and disc drives (cache controllers) that keeps frequently accessed instructions more readily accessible. (See also Bus )

Cache
This is a small section of the computer’s memory.

Cache
Part of the computer memory that stores information for quick retrieval. When a computer displays a web page the information is stored so that if the page is visited again information can be retrieved from within the local computer rather than being downloaded from the network. Information obtained from the internet is stored in a temporary file (cache) which has a pre determined capacity so that when it becomes full new information replaces the old. Cached files can be removed from your computer but it does not happen automatically.

CACHE
A region of memory where frequently accessed data can be srored for rapid access.Browsers such as Netscape or Microsoft Internet Explorer hold copies of recently visited web files,both HTML,and binary files ,in disk memory.This disk space memory is called as the cache.It offers the advantage of much quicker loading when files are stored on disk than when they must be transferred from the web.

Cache
A portion of RAM used for temporary storage of data which must be accessed very quickly. In applications which run from CD-ROMs, the cache is typically used to store directory files.

Cache
Pronounced like "cash", not "catch", and definitely not "cashé". There are many different types of caches but they all serve basically the same purpose. They store recently-used information in a place where it can be accessed extremely fast. For example, a web browser like Netscape Navigator uses a cache to store the pages, images, sounds, and URLs of web sites you visit on your hard drive. With this neat strategy, when you visit a page you have recently been to, everything doesn't have to be downloaded to your computer all over again. Because accessing your computer's hard disk is much faster than accessing the Internet, this speeds up web browsing significantly. Your computer also uses disk caching, which stores information you have recently read from your hard disk in the computer's RAM. Since accessing RAM is much faster than reading data off the hard disk, this helps speed up common functions on your computer. One more type of cache is a processor cache which stores small amounts of information on or next to the processor. This helps make the processing of common instructions much more efficient, thereby speeding up computation time. Neat, huh?

cache
A source of subsistence and supplies, typically containing items such as food, water, medical items, and/or communications equipment, packaged to prevent damage from exposure and hidden in isolated locations by such methods as burial, concealment, and/or submersion, to support isolated personnel. See also concealment; evader; evasion; recovery; recovery operations. (JP 3-50)
  

62913
State: ILLINOIS
City: CACHE

73527
State: OKLAHOMA
City: CACHE

Cache
(n.)
A hole in the ground, or hiding place, for concealing and preserving provisions which it is inconvenient to carry.
  

cache

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Noun
1. a hidden storage space (for money or provisions or weapons)
(hypernym) storage space
(derivation) hoard, stash, lay away, hive up, squirrel away
2. a secret store of valuables or money
(synonym) hoard, stash
(hypernym) store, stock, fund
(derivation) hoard, stash, lay away, hive up, squirrel away
3. (computer science) RAM memory that is set aside as a specialized buffer storage that is continually updated; used to optimize data transfers between system elements with different characteristics
(synonym) memory cache
(hypernym) buffer, buffer storage, buffer store
(hyponym) disk cache
(classification) computer science, computing

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Verb
1. save up as for future use
(synonym) hoard, stash, lay away, hive up, squirrel away
(hypernym) save, lay aside, save up
(derivation) hoard, stash

cache

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cache
\cache\ (?), n. [f., a hiding place, fr. cacher to conceal, to hide.] a hole in the ground, or hiding place, for concealing and preserving provisions which it is inconvenient to carry. [
cache
n
1. a hidden storage space (for money or provisions or weapons)
2. a secret store of valuables or money [syn: hoard, stash]


3. (computer science) ram memory that is set aside as a specialized buffer storage that is continually updated; used to optimize data transfers between system elements with different characteristics [syn: memory cache]
v : save up as for future use [syn: hoard, stash, lay away, hive up, squirrel away]

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  similar words(19) 

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 second level cache 
 fully associative cache 
 set associative cache 
 level 2 cache 
 memory cache 
 cache miss 
 cache conflict 
 virtual cache 
 pb cache 
 cache hit 
 cache line 
 secondary cache 
 primary cache 
 level 1 cache 
 level two cache 
 l2 cache 
 l1 cache 
 direct mapped cache 
 level one cache 

cache
folachán

Cache
tsorau, tsoraya

cache
Readily accessible computer memory for efficiently storing frequently-accessed items.

CACH
Cache, Inc.
Exchange: Nasdaq
Owns and operates high fashion women's apparel and accessory specialty stores, focusing on social occasion dressing and formal black tie affairs.

Cache
a placement of food and / or supplies along or near a trail or route of travel for future use.

Cache

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Cache (disambiguation)

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