The speed of the entire computer largely depends on the speed of the RAM, so its choice is no less important than buying the “right” processor or motherboard. Well, among the most important parameters of any RAM, frequency and timings stand out. But if everything is clear from the first, then the timings for many remain a dark forest. Today, we will tell you what is hidden behind this incomprehensible set of numbers, and what meaning it has.
What are RAM timings?
Speaking in a very simple language, RAM is an array with a two-dimensional table, the cells which store the necessary information. And arrays with cells of the same size, in turn, are combined into so-called banks.
To perform any operation on the data in this table, the controller and the memory chip require a certain number of memory bus clock cycles. Well, timing is the number of such cycles, or the number of cycles by which the execution of a certain memory operation will be late. Hence the name itself – timing or delay.
Actually, that is why two RAMs with the same frequency, but with different timings, will work differently, and the memory with a lower delay will be the fastest.
What timings are
Each operation with RAM can be divided into several stages. Therefore, the characteristics of any RAM bar indicate several timings – delays that occur at a certain stage of working with memory. Timing numbers indicate the following operations:
CL: CAS Latency – the number of cycles that elapses from sending a request to memory until the start of a response to it.
tRCD: RAS to CAS Delay – the number of ticks that the controller needs to activate the desired line of the bank.
tRP: RAS Precharge – the number of cycles to charge and close one row, after which it becomes possible to activate the next row.
tRAS: Row Active Time – the minimum number of cycles during which the row will be active. It cannot be closed before this time.
All these timings are indicated in the RAM parameters in the exact order that we have given. Take, for example, Patriot Memory VIPER STEEL DDR4-3733 CL-17 21-21-41. We see that it belongs to the DDR4 type and operates at a clock frequency of 3733 MHz. It takes 17 cycles to start responding to an incoming request (CL). Activation of the desired row takes 21 cycles (tRCD) and the same number of cycles is spent on its closing and activation of the next row (tRP). Moreover, the line itself can be closed no earlier than after 41 cycles (tRAS).
As you can see, each number in the name of the RAM has its own meaning. And, having understood this, you can easily choose the most suitable RAM for you.
How to check RAM timings
The values of RAM timings can be viewed on its page in any more or less self-respecting store or on the manufacturer’s website. If you want to see the characteristics of the memory you already have installed, you can use CPU-Z or similar utilities.
How to choose the fastest RAM
In short, the frequency of RAM is more important than timings, but at the same frequency, the RAM with less delay will be the fastest. Actually, it is on the basis of this that it is worth choosing the most suitable RAM strips for you. In general, this algorithm looks like this:
- Decide on the type of RAM that your computer supports – DDR3, DDR4, DDR5, etc.
- Decide on the amount of memory you need.
- Find out what frequency of RAM your PC’s processor and motherboard support.
- Pick up the RAM sticks that work at the maximum frequency available for your computer.
- Among these bars, choose models with minimal timings.
