dido:public:s_cli:05_contents:01_prt:03_langconst:07_memandstor:start
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dido:public:s_cli:05_contents:01_prt:03_langconst:07_memandstor:start [2021/08/11 12:55] murphy [DEFINE, CREATE, versus DECLARE] |
dido:public:s_cli:05_contents:01_prt:03_langconst:07_memandstor:start [2021/08/13 13:17] (current) murphy |
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| Memory and Computer Storage is not a single thing, it is a hierarchy based upon how much memory needs to be accessed and how fast it needs to be accessed. Figure {{ref>MemHier}} summarizes the hierarchy as a pyramid. the width of each band in the pyramid represent the amount of data that can be stored. As a general rule, if there is a lot of data, then to keep the costs affordable, the slower the access is to the memory. At the lowest level, the memory persists after the power is turned off. At the top of the pyramid, the data is lost when the power is turned off. | Memory and Computer Storage is not a single thing, it is a hierarchy based upon how much memory needs to be accessed and how fast it needs to be accessed. Figure {{ref>MemHier}} summarizes the hierarchy as a pyramid. the width of each band in the pyramid represent the amount of data that can be stored. As a general rule, if there is a lot of data, then to keep the costs affordable, the slower the access is to the memory. At the lowest level, the memory persists after the power is turned off. At the top of the pyramid, the data is lost when the power is turned off. | ||
| - | Designing for high performance requires considering the restrictions of the memory hierarchy, i.e. the size and capabilities of each component. Each of the various components can be viewed as part of a hierarchy of memories (m1,m2,...,mn) in which each member mi is typically smaller and faster than the next highest member mi+1 of the hierarchy. To limit waiting by higher levels, a lower level will respond by filling a buffer and then signaling for activating the transfer. | + | Designing for high [[dido:public:ra:xapend:xapend.a_glossary:p:performance|performance]] requires considering the restrictions of the memory hierarchy, i.e. the size and capabilities of each component. Each of the various components can be viewed as part of a hierarchy of memories (m1,m2,...,mn) in which each member mi is typically smaller and faster than the next highest member mi+1 of the hierarchy. To limit waiting by higher levels, a lower level will respond by filling a buffer and then signaling for activating the transfer. |
| There are four major storage levels(( | There are four major storage levels(( | ||
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| )): | )): | ||
| - | * **Internal** – Processor registers and cache | + | * **Internal** – [[dido:public:ra:xapend:xapend.a_glossary:p:processor|Processor]] registers and cache |
| * **Main** – the system RAM and controller cards | * **Main** – the system RAM and controller cards | ||
| * **On-line mass storage** – Secondary storage | * **On-line mass storage** – Secondary storage | ||
dido/public/s_cli/05_contents/01_prt/03_langconst/07_memandstor/start.1628700900.txt.gz · Last modified: 2021/08/11 12:55 by murphy
