Question Adding more RAM

[Drosef]

Hi, I'm looking to pick up some more RAM and have no idea how compatibility works. I have a Gigabyte GA-Z170X-UD3 ATX LGA1151 motherboard with 2x4GB sticks of Kingston Fury DDR4-2666. If I pick up an additional 2x8GB sticks of Team T-Force Vulcan DDR4-3000 would I be able to use the old sticks in slots 1&3 with the new ones in 2&4? Or should I just give up on the old ones and only use the new sticks?

 

[Darkbreeze]

So that I don't have to retype it all, check this link. The information there is relevant to your question, even though it is regarding a different platform.

https://forums.tomshardware.com/threads/amd-ram-compatibility.3210050/post-19785792

That being said, the fact that you have sticks which are only 2666mhz, which is basically within the JEDEC guidelines for default memory operation on Intel platforms, although the default for Z170 is 2133mhz, you can PROBABLY add sticks without running into major issues. I would not try to mix brands though unless there is no other choice. In fact, you would be REALLY wise to try and get the exact same model of kit as what you have now, even though that is not always a guarantee of compatibility either. It is, at least, going to give you a higher PROBABILITY of success, regardless that nothing is guaranteed.

If you install CPU-Z and click on the SPD tab, then select one of your memory slots that has a DIMM installed from the drop down menu in the top left, then look in the field listed as "part number" it should give you the model of your memory kit. We can then try to find an identical kit, or at least one with speed and timings that match as closely as possible.

 

[Encryption+]

You may be able to make it work so long as you get the exact same brand and type of ram, but personally I'd recommend getting a complete set of four sticks of whatever size RAM your wanting and sell of the old sticks, or just keep them in case you ever want them for something else. Also unless your overclocking putting 2666 sticks in that motherboard will just waste the speed of the ram, since the board will self limit it to 2133 as that's the max non-overclocked speed of the board.

 

[geofelt]

A perennial question.
Here is my stock answer:

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.

If you do buy more disparate sticks, they should be the same speed, voltage and cas numbers.
Even then your chances of working are less than 100%
I might guess 90% success for intel and less for amd.

What is your plan "B" if the new stick/s do not work?

If you want 16gb, my suggestion is to buy a 2 x 8gb kit that matches your current specs.
Then, try adding in your old 8gb,
If it works, good; you now have extra ram.
If not, sell the old ram or keep it as a spare.