Ever notice your PC stutter while gaming or running multiple programs? It might be due to slow RAM latency. You’ve likely seen CAS latency (CL) advertised on RAM. This tells you how many clock cycles it takes to access specific data, but it doesn’t give the whole picture.
True RAM latency, measured in nanoseconds (ns), combines CAS latency with the RAM’s frequency. As such, a lower RAM latency is better as it means your RAM will perform faster, leading to smoother performance. Well, we have developed our latency calculator tool that will help you calculate the RAM latency of your kit. Plus, we’ll show you how to calculate true RAM latency and also tell you why it’s more important than just CAS latency when choosing RAM.
RAM Latency (ns) = (CL x 2000) / MHz
Our program works very simply to give you the exact latency of your RAM. It takes the CL (or CAS) number of your RAM kit and multiplies it by 2000. After that, it divides the resultant number by RAM speed to get the final RAM latency.
Why RAM Latency Matters
Since RAM frequency and CAS latency both indicate different performance metrics, you shouldn’t rely on either of them too much when buying RAM. This is where our tool to calculate RAM latency (measured in nanoseconds) comes in; it factors both RAM frequency and CAS latency to give you a balanced metric for measuring your RAM’s performance.
FAQs
You can calculate RAM latency by multiplying CAS latency by 2000 and then dividing the answer by your RAM speed, or you can just use our program.
A 3600MHz RAM can transfer more data in a second than the 3200MHz, ignoring other factors like timing latencies and RAM latency in general; a 3600MHz RAM is better than 3200MHz.
For DDR5 RAM, any CAS latency below 36-38 is good, and for DDR4 RAM, I would recommend going with any RAM that has CL18 CAS latency.
CAS latency is the first type of timing latency that tells us how quickly the RAM can send back the data your CPU has asked for. The lower the CAS latency, the better and faster your PC will run.
RAM frequency tells us how many cycles the kit can make in a second to transfer data to and from the RAM modules. As such, the higher the RAM frequency, the faster and better the RAM is.