Choosing RAM can be daunting, because this decision may have a tangible impact on your user experience. How many browser tabs can you keep open, how many layers can you have open in Photoshop, & how fast will your trò chơi load? All of this is directly affected by your choice of RAM.Bạn đã xem: Cas 15 vs cas 16 là gì

How does RAM work?

Let us use a busy highway as an analogy. The number of RAM sticks is kind of like the number of lanes on the road: the more sticks of RAM you have, the more lanes you have open, và the more cars the road can hold at a given time.

Bạn đang xem: Cas 15 vs cas 16 là gì

Bạn đang xem: Cas 15 vs cas 16 là gì

The kích cỡ of your RAM, in this analogy, would be how many cars each lane can hold. Và the speed of your RAM is like the speed limit sign posted on the highway.

Therefore, a stick of 8GB RAM with a clock speed of 2666mhz can process 8GB of data at a given time, và 2666mhz is the tốc độ at which the information will be processed.

This is why adding more RAM will not necessarily make your computer faster: you’re adding more lanes lớn the road and more car capacity, rather than increasing the tốc độ limit. Adding more RAM may be useful for users in certain RAM-hungry situations (heavily tabbed Chrome users, 3 chiều rendering/modeling program users, và recent console—e.g. PS3, Wii U—emulation users), but more RAM is almost never the answer as to lớn why a computer is not running a trò chơi at your desired performance level.

How vị you determine RAM latency?

The first column represents CAS latency, also known as “Column Access Strobe.” This is the number of clock cycles that pass between when an instruction is given và when the information is made available. If you tell someone to “duck!”, CAS latency would be the delay between when you command them lớn duck và when the other person reacts.

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To calculate the true latency of your RAM in nanoseconds, use the following formula:

(CAS latency/RAM clock speed) x 2000 = latency in nanoseconds

If you have a CAS of 15 and a clock speed of 2400mhz, this would be your true latency:

(15/2400) x 2000 = 12.5 nanoseconds

If you have a CAS of 17 và a clock speed of 2666mhz, this would be your true latency:

(17/2666) x 2000 = 12.75 nanoseconds

Similarly, the comparison of CAS latency between RAM options of identical clock speeds is where CAS matters most. A stick of DDR4-3600 RAM with a CAS of 15 has a true latency of 8.33 nanoseconds, while a same-size/same-speed stick with a CAS of 19 has a latency of 10.56 nanoseconds. In this case, the DDR4-3600 RAM with a CAS of 15 is objectively better than the DDR4-3600 RAM with a CAS of 19.


How bởi you choose RAM?

Motherboards & CPUs are rated for the maximum amount & speed of RAM they can handle. If your motherboard & CPU is only rated up to lớn 3600mhz, then you should only purchase or overclock RAM up to 3600mhz. However, a quick perusal will reveal that there’s over a hundred variants of 3600mhz RAM available. If you narrow it down lớn the form size of the RAM, perhaps to 16gb (2 x 8GB), you still have a few dozen options. This is where CAS (and cost) comes in.

When dealing in nanoseconds, the difference may not seem significant—and it can certainly be argued that, for the average user, the difference between a CAS of 15 và a CAS of 19 is not worth breaking the bank. But when choosing between RAM options within budget, you should choose the lowest CAS at a given tốc độ for the best performance.