RAM Latencies

Everybody who uses computer always complain about RAM.....  that they have less RAM because of which they r not able to play their favorite games.....But have u ponder about certain facts while purchasing your RAM. Most of the time, we always see its clock speed in MHz like 233/400/533/677 etc. These r just the clock speeds but their is something more which we must look for & that is,it's latency figures which r usually written somewhat in this way "3-3-2-8"

Before exploring the meaning of these numbers, first of all, we must know what is latency.Latency means how much late or how much clock cycles r needed before the works get done....

Now coming to theses 4 digits.

1st digit represent CAS (Column address strobe)It means the delay between registered read and data output.In our example,we have taken 3.This means that 3 clock cycles will be needed before data will be send.

2nd digit stands for RCD (Row-Columns Delay).Before writing anything into RAM, address needs to be generated & address will be generated in row-column manner.so this type of delay equals to total time spent defining space & performing read & write operation.

3rd digit stands for RP(Row Pre-charge time).when ever anything is written into RAM than data is written row-wise.until one row has not finished new row will not be initialized.so the time required to terminate one row & start another is called RP.

4th digit stands for RAS(Row Address strobe)This means the amount of cycle spent in accessing data on a particular row.

All these digit represent number of clock cycles to perform required operation.Lower the values,  higher the speed.

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