[SOLVED] How important is CAS Latency?

[Nameless9]

I have an Asus TUF FX505DT laptop that came with single channel 8GB 2666MHz memory. I was hoping to buy another stick of the same model to increase my memory to 16GB dual channel. The model number of the memory is M471A1K43DB1-CTD, but I wasn't able to find a reputable seller online that had an exact match.

There is an Amazon listing for a model with a very similar model name to mine (the "DB1" is "CB1" instead): Samsung M471A1K43CB1-CTD 8GB DDR4 2666MHz

The speeds of both are identical at 2666MHz and both are 8GB, but the one on Amazon has a CAS Latency of 19 while the current RAM in my laptop has a CL of 17. Can I still buy the one from Amazon and have it run without problems? Or am I better off just buying a new set of 2x8 RAM from a different brand and discarding the existing one I have?

 

[NightHawkRMX]

There is no way to know one way or another until you test it.

 

[geofelt]

At equal speed, a lower cas performs better.

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, particularly ryzen can be very sensitive to ram.
You take your chances.

My suggestion is to go to a ram web site like crucial and access their ram upgrade app.
Enter the make/model of your laptop and you should get a list of supported upgrades.
Adding 8gb is likely to work, but no guarantees.
Replacing with a 2 x 8gb kit is more expensive but reduces your odds of having issues.

 

[Nameless9]

Thanks for the response, I think I'll just play it safe and use Crucial's compatibility tool. It's a shame I have to spend a little extra, but it's a lot better than ending up with ram that's no good.