Question Question regarding adding new RAM

[GuapoDaChamp]

I'm running on a Asus Crosshair V Formula-Z Mobo. I currently have G.Skill F3-10666CL9D-8GBXL Ripjaws X Series 2 x 4GB


Was wondering if I purchased G Skill F3-12800CL9D-8GBXL Ripjaws X Series 2 x 4GB would this be compatible? Would these just run at the slower speed to the ones I currently have in?

 

[Dark Lord of Tech]

If they did work , good chance they won't , they will perform at the slower speed.

 

[geofelt]

If you need 16gb, and that is usually a good idea, buy a 2 x 8gb kit of the speed you want and keep the old ram as a spare.
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, can be very sensitive to this.
This is more difficult when more sticks are involved.

 

[GuapoDaChamp]

I would get another of the same 2x4 of the same sticks, but I can't find the same exact ones anywhere. So probably just best to get 2 new 2x8 GB sticks and leave it better with 2 at 16gbs. Now when I install them is there a specific way to make them run in dual channel

 

[geofelt]

You can never get the exact same sticks. There will be subtle manufacturing differences and they may not work with your old ram.
Save yourself some potential trouble and buy a single 2 x 8gb kit.

Your motherboard manual should specify the preferred slots for the ram. Namely, one stick in each channel and you will get dual channel operation.
To confirm, run cpu-Z where it should say dual.