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
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.
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
i believe it refers to "cas latency"
CL5
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
The primary difference between the PC2-5300F-555-12-J0 and the 2RX4 PC2-5300F-555-11-E0 lies in their specifications regarding latency and rank. The first model has a CAS latency of 12, while the second has a lower CAS latency of 11, which typically means the latter may offer slightly better performance. Additionally, the "2RX4" designation indicates that the second module is a dual-rank memory, which can affect memory bandwidth and performance in certain configurations compared to single-rank modules.