Blev själv lite nyfiken på det där med CAS. Har alltid gått på att det ska vara låga värden utan att riktigt veta varför. Nu vet jag lite mer iaf
Från: http://bugclub.org/beginners/memory/cas.html
"In computer memory technology, CAS, Column Address Strobe, is a signal sent to a dynamic random access memory (DRAM) that tells it that an associated address is a column address. A data bit in DRAM is stored in a cell located by the intersection of a ColumnAddress and a RowAddress. A RAS (row address strobe or select) signal is used to validate the row address.
A DRAM memory can be thought of as a matrix, kind of like a spreadsheet with memory cells instead of numbers and formulas. Like the spreadsheet, each cell has a row address and a ColumnAddress (like "AA57" or "R23C34" in the spreadsheet). There is also a RAS signal, which is stand for "Row Address Strobe".
To understand how CAS works is is best to walk through a simplified version of how the memory is actually read. First, the chip set accesses the ROW of the memory matrix by putting an address on the memory's address pins and activating the RAS signal. It then waits a few clock cycles (known as RAS-to-CAS Delay). Then, the ColumnAddress is put on the address pins, and the CAS signal is activated, to access the correct COLUMN of the memory matrix. Then, it waits a few clock cycles (this is known as CAS latency) and then the data appears on the pins of the RAM."
CAS (latency) 3 borde sålunda vara 50% långsammare än CAS 2 för den sista operationen. Vad det gör för totalen är dock lite oklart. Någon som vet?
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