Difference between different RAMs

[Kiwis_FN]

I was just messying around on pcpartpicker, and looking at RAM. I saw that 2400mhz CL12, 3000mhz CL15, 3200mhz CL16 and 3600mhz CL18 all have a "first word latency" of 10ns. However the 3000mhz CL15 is the cheapest. Will one give me better performance or because the "first word latency" is the same it will be the same performance. 

If there isn't a performance difference then I might in the future overclock the RAM. Which one would give the most potential for overclocking.

 

Thanks in advance

[Chris Pratt]

The CL number is the CAS latency, which refers to how long it takes to get the result of the READ command. It's somewhat tied to clocks, as you want it to roughly happen once a clock cycle. If you notice all the numbers here are 1/2000 of the clock speed, because first DDR is double data rate, so the actual clock is half that, and second it's 1000/s, or milliseconds (what CAS latency is measured in). Assuming a CL 1/2000 of the clocks in all cases, the fastest clock is your winner.