| Put them together CAS + Latency = CL |
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CL stands for CAS Latency. This is the amount of time that it takes to retrieve data from the memory module. First a RAS (Row Access Strobe) signal is activated and then the CAS signal is activated to access the precise location of the requested data; the data is then transmitted. CAS Latency intervals are identified in clock cycles; for example, CL2/CAS-2 means it will take two clock cycles for the initial data stream to be sent. Therefore, CL2/CAS-2 modules can run faster than CL2.5/CAS-2.5 or CL3/CAS-3 modules.
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How does CAS Latency impact my system?s performance? |
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The areas of computing most affected by CAS Latency will be memory-hungry applications such as computer games and other graphics intensive programs, as well as multimedia applications such as video editing and home theater systems. A switch from CL3/CAS-3 to CL2/CAS-2 will show a noticeable gain in overall system performance while running these memory intensive applications. CL3/CAS-3 will be adequate for most memory users that run basic web browsing and small office applications; CL2/CAS-2 modules provide low latency for those seeking higher performance in demanding applications. When overclocking a system, memory timings can range from low latency CL2/CAS-2 overclocking modules, to higher latency CL2.5/CAS-2.5 or CL3/CAS-3 modules designed for extremely high memory speeds.
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What is Latency? |
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| Latency is the amount of time one system component is waiting to get what it needs from another system component. In terms of memory, it?s the interval between a processor?s stimulus and the memory?s response. |
What is CAS? |
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Short for Column Access Strobe, CAS is a signal sent by the processor to a DRAM circuit to prompt a column address. DRAM stores data in a series of columns and rows; each bit of data is filed in both a column and a row. Data is retrieved from the DRAM by the processor using CAS and RAS (Row Access Strobe) signals, much like pinpointing a location on a map using coordinates.
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