What's the rule for memory speed vs ns ram?

[bigredelmo80]

Like 5ns is equal to xxx mhz.
Or 4ns ram is capable of 250mhz etc.?
I forgot

 

[Gunslinger08]

1000/ns

1000/4ns = 250mhz
1000/3ns = 333mhz
etc

Josh

 

[Soccerman]

ns stands for the length of time in nanoseconds that it takes for one clock cycle to pass. there are 1 billion nanoseconds in a second so a nanosecond is 0.000000001 seconds long.

so then it's easy to find how many clock cycles will go by in a second (cycles/second=hz) if we know how long each clock cycle is.

1/0.000000004=250 000 000hz=250mhz.