An ad for memory might sometimes give the CAS Latency value within a series of timing numbers, such as 5-5-5-15. The first value is the CAS latency, which would mean that in this case, this module is CL5. The second value is RAS latency.
25
CL5
i believe it refers to "cas latency"
In general, if you want better performance, lower cas latency is better.
CAS and RAS Latency are two ways of measuring speed
CAS (column access strobe) Latency and RAS (row access strobe) Latency
CAS Latency rating.
CL: (CAS Latency) or Column Address Strobe Latency is a measurement of delay of the chip's process. So the lower the CL number the lower the latency will be. So your answer is cl5.
CAS Latency
Latency. The main latency figure is CAS Latency, also called CL Latency is the number of clock cycles that a RAM chip has to wait after being read or written, before it is ready to be read or written again. A lower latency means less time the computer has to wait before it can do another memory operation.
For DDR(CAS / DATA RATE) * 2000 = X ns(7/1333MHz) *2000 = 10.5 ns
CL is the same as CAS Latency and RL is the same as RAS Latency. They both pertain to the number of clock cycles it takes to write of read a colum or row of data off a memory module. Source:CompTIAA+ Guide to Managing and Maintaining Your Pc by Jean Andrews Pg.207
THE "CL" stands for "CAS Latency" the number of clock cycles it takes before data starts to flow once a command is received. Low CAS latency is faster than high CAS. You would not be able to tell the difference between waiting 4 clock cycles as to 5 clock cycles since a 200MHz bus is 200 million clock cycles a second....go with whatever is cheaper and easy for you to handle when installing it. Personnally, I'd go for the 2X2GB, that is two less sticks of RAM you have to worry about going dead on you.