Question XMP and 2 dual-channel memory

[sven.silva]

Hello!
I plan on expanding my RAM to 32Gb because 16 are not really enough with video editing and stuff.
I actually have a 2x8Gb kit 3,600 Mhz from G.skill and I'm planning on buying the exact same kit to get the double RAM I need. I've already read stuff here about potential problems I could get by using 2 separate even though identical kits so I'm already briefed with that.
But there's nothing about that question:
Does XMP work with 2 dual channel memory kits?
My mobo is an Asrock z270 Pro4, and the only notice I saw about RAM frequency is about using 3733+ Mhz RAM where it only works with one single module.
I'm asking because knowing that my mobo can't handle more than one module at 3733 Mhz (though it handles 2x3600), will it handle 4 of them at 3600?
Does XMP in general handle all the modules as long as they're working with the same CAS and frequency?
Thanks in advance for your help!

 

[Darkbreeze]

Yes, it works. You will want to populate one kit in the second and fourth slots, which are A2 and B2, and the new kit in the first and third slots, which are A1 and B1. Some boards have different naming schemes for the DIMM slots such as DDR4_1 and DDR4_2 for the second and fourth slots, but they are STILL going to be the same slots and you want to use 2 and 4 for one pair, and 1 and 3 for the other pair. That will give you the best chance of two kits working together AND working in dual channel. If they work, they will almost always work in the multiple channel configuration.

 

[sven.silva]

Yes, it works. You will want to populate one kit in the second and fourth slots, which are A2 and B2, and the new kit in the first and third slots, which are A1 and B1. Some boards have different naming schemes for the DIMM slots such as DDR4_1 and DDR4_2 for the second and fourth slots, but they are STILL going to be the same slots and you want to use 2 and 4 for one pair, and 1 and 3 for the other pair. That will give you the best chance of two kits working together AND working in dual channel. If they work, they will almost always work in the multiple channel configuration.

And so will the XMP work on all 4 sticks?

 

[Darkbreeze]

Yes. There are two dual channel "channels", channel A and channel B, for any dual channel motherboard with four DIMM slots. And technically you could populate all four DIMMs in any of the four DIMM slots, and still see dual channel operation for all four sticks, but you'll usually have more success of them playing nice together, at all, when you use the DIMMs that came in the SAME kit, together. Which is why I say to use the original kit in slots 2 and 4, and the new kit in slots 1 and 3. Or, reverse of that is fine too so long as you keep the sticks that came together on the same channel.

No need to verify the population rules either, it is the same for all four DIMM slot dual channel motherboards, since as far back as I can recall their BEING dual channel configurations.

 

[Calvin7]

Memory manufacturers won't guarantee the kind of combinations you propose to be compatible together.
Such combinations often result in the memory no longer being able to operate at rated specifications. You are free to do your own compatibility testing with no guarantees if you choose to make such combinations.