What's RAM Timings? (CL30, CL40, etc.)

[Leahh]

What's RAM timings? Like what do they mean, and which ones are good?
I don't know at all what they mean, so please explain like I'm 5.

Thanks in advance

[Eigenvektor]

It tells you how long (how many clock cycles) the CPU has to wait before data it has requested will be available. In general lower numbers are better. But since it is measured in clock cycles, rather than say milliseconds, a higher number at a higher clock speed may be equal or even better to a lower number at a lower clock speed.

 

You can think of it like ordering something from an online shop. The latency tells you how long it takes before the stuff you ordered arrives at your door.

[RONOTHAN##]

Explained like you're 5: the amount of clock cycles it takes for the memory to do something. Lower is better, though since they're measured in clock cycles, you will need to figure out their relative latencies to figure what their actual performance is (the formula for at is timing * 2000 / data rate, so CL30 at 6000 would become 10ns, or CL36 at 8000 would be 9ns)

 

Explained a bit more accurately: There are a ton of different commands that the memory controller can tell the memory to accomplish, each of which takes a certain amount of time. Since a memory stick is rather dumb (as in it has little to no logic circuitry on board), it has no idea when these operations are complete and no way to tell the memory controller "Hey, the data is ready" or "I'm done writing data now, I can do something else." Because of this, the memory controller has a set of timings which are effectively an amount of clock cycles that a certain memory operation will be done by. There's one for every memory operation that the memory controller does.