CL9-CL11???

[PoshBoyGames]

Can someone explain what CL is? Is CL11 better than CL9?

[kuzimins]

cl 9 is better

[coen113]

it stands for Cas-Latency, Less is better. if you want to pick ram, get any cl9 1600-1866 ram

[Hans Christian | Teri]

There's a great article about memory latency on Wikipedia that you should read of you truly want to understand what's going on. Other than that for mixed use 1866MHz CL9 is the best balance between latency and frequency that I have come across.

[deathjester]

Lower the latency better the ram. Higher the ram speed, latency changes. CL11 is just bad though unless you are hitting super high frequencies. First number matters the most. As in 9-10-9-28 1866 > 9-9-9-24 1600, 

 

There's a great article about memory latency on Wikipedia that you should read of you truly want to understand what's going on. Other than that for mixed use 1866MHz CL9 is the best balance between latency and frequency that I have come across.

 

By far the best price performance option. 2133 cl9 is better but usually stupidly expensive. Some 1866 cl9 1.5v will oc to 2133 cl9, some won't.

 

If 1866 9-10-9-28 1.5v is around the same price or close to 1600 9-10-9-28 1.5v? Get it. Voltage gives you headroom. You want 1.5v at anything under 2133.

 

Ram prices are FUBAR atm. So when this stuff is like 5 bucks more then 1600 ram?

 

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231538

 

Get it. That will probably do 2133 cl9 and the timings are ridiculously good at 1866 if you don't want to mess with OC'ing the ram.  That ram absolutely blows away almost every 2133 kit sold. 

[mgsstar]

Great article describing it from Crucial: 

 

 

What is CAS latency and how do I determine what I have?

CAS latency (also referred to as latency) is the amount of time it takes for your memory to respond to a command. Specifically, it is the length of time between memory receiving a command to read data, and the first piece of data being sent from the memory. 

Unless you are a computer enthusiast looking to push every last bit of performance out of your system, CAS latency needn't be a deciding factor when purchasing memory modules. 

You may see CAS latency (clock latency) referred to as CAS#, CL#, CAS=# or CL=#. The performance difference between CAS latency ratings is virtually undetectable. 

Source:http://www.crucial.com/kb/answer.aspx?qid=3657

CL9 is better but I have used CL11 and CL9 ram on my system before and didn't really feel any performance difference.