I realize this thread is a bit old. But I've goofed with computer building, over clocking, the whole 9. It may be useful to someone else searching down the road. I can't get into what each latency mark means (partially bc I don't recall off the top of my head), but it's not something you need to pay attention to. Not with the amount and speed of ram you have. It's like comparing a Ferrari and a Mclaren, saying one does 210 mph and the other 208mph. Nobody would buy a car like that based solely on that number. That's kind of what comparing theses latencies is like. You would buy the ram based on reliability ratings, speed, and what you can fit/afford. I doubt that you would see a difference with those latencies, with any application. Like @DonnyThompson said, it's milliseconds. But also, it's situational. Those numbers are arrived at with a series of tests. We are assuming that those tests will be relevant to real world performance. At the level you are speaking of, the latencies are not distinguishable except with speed tests. Meaning, you aren't going to feel a difference. DDR4 at 2400, that's ridiculously fast already. It would be something I would pay attention to, only if my goal was overclocking, bc I know what latencies I can run. For most normal people, you would want to buy based on maximum speed and amount you can afford....then look at the rams reviews. If it's reliable and the max speed you can fit, latencies are not important. Reliability is a much more important factor than those latencies. Ram can be finicky. One thing to keep in mind is that some ram is made for overclocking. It's made to run at higher voltages, and with higher heat. As such, it's usually more expensive. Occasionally, you will see ram speeds listed, but it's at 1.5 volts. 1.2 is typically what your computer is feeding it. So if it's rated at 1.5, and you install it at 1.2 (they are usually 1.2 stable) it's not going to run at the speeds listed anyway. You may already know that bc everything I saw listed was 1.2 volts. So, overclocking ram is not of any use to people, unless they overclock it. It will be rated as faster than the other ram sticks, but once installed in YOUR computer at 1.2 volts, it's no faster than other ram sticks. I've seen quite a few people buy "overclocking" ram, and paying a hefty price, thinking it's better/faster. Unless you go in and change the voltages and latencies, the ram is the same as it's competition. Oc'ing the ram isn't super hard, but it takes a little practice to get it stable. And with the speed of ram these days in general, oc'ing isn't really necessary. Just don't buy that ram thinking that it's faster. At 1.2 volts, it's not. And if one doesn't go in the system to change the voltages and latencies, they just got ripped off on their ram purchase.