I have an Asus motherboard, H97-E, with G.SKILL's 2X4GB DDR3-1600 CL-9.
I wish to expand to 16GB, but find this excat type, is quite scarce nowadays. BUT a DDR3-1600, CL-11 can be found in stores near by.
Is it possible to combine CL-9, and CL-11 on same motherboard ?
Is my motherboard capable of running a CL-11 ( assuming mixing is not possible, and using only CL-11 )?
24 Answers
CL = Column Address Strobe Latency, which shows the number of clock cycles that pass from when an instruction is given for a particular column and the moment the data is available. In general, the lower the CAS latency the better within a given memory technology.
So, a CL-9 will be faster than a CL-11, all other things being equal.
Your motherboard's manual says not to mix memory modules with different latencies.
How much it slows down if you change to all CL-11 may not be noticed. A Tom's Hardware review showed a 2 % slowdown when CL-11 was tested vs CL-9, and that's before other hardware choices were factored in.
Since, with the 2014 design of your motherboard and its H97 chipset, at most you can run an Intel Core i7-5775C or i7-4790K CPU, so the difference won't be earthshaking, or even perceptible.
6Is it possible to combine CL-9, and CL-11 on same motherboard ?
Yes; However, the highest latency module, will determine the latency for all modules installed in your system. This means all modules installed would have a CAS (Column Access Strobe) latency of CL-11. However, ASUS does not recommend you mix modules with different CAS latency, nor does ASUS explicitly indicate your motherboard supports that configuration.
Is my motherboard capable of running a module with a CAS latency of CL-11?
Memory compatibility with a motherboard is not determined by the CAS latency of the module typically.
Reference: CAS latency
2K7AAY and Ramhound provided good answers.
Another thing to pay attention - the voltage.
You may check your current RAM voltage and buy new stick(s) that need the same voltage.
Otherwise, from my experience, You'll have problems.
1I am using TwinMOS 2GB DDR3 which is CL-9 and 8GB TwinMOS CL-11 on my Asus H61M-K from the day windows 10 first pre-release. For me nothing seems wrong, but yes, they suggest choosing RAM with the same CAS latency for adaptability.
