latency setting(n.) A memory setting in a computer system's BIOS that specifies the speed at which memory receives and sends data. The lower the latency number, the better the system performance and the more stress the system is put under, which can lead to system instability, particularly in overclocking scenarios.
Latency settings typically are expressed as a four-digit number separated by dashes, such as 2-2-2-5. The first number always represents the CAS latency, as that type of latency typically is the most important. The second number typically is the RAS-to-CAS delay, followed by the RAS precharge (which is how long the memory is powered so that data can be read from it) and typically concludes with the ACT to precharge delay, which is normally the highest number of the four settings.