Compatible ram for existing motherboard?

[rorton]

I have a NAS running unraid with a ASRock B450M Pro4 motherboard, and 2 x 16GB Crucial Ballistix BLS16G4D26BFSB.16FD
I'd like to add another 32GB to this board, existing ram is DDR4 2666MHz

Can I add pretty much any DDR4 ram, and will it just run at the speed of the existing?

something like

Crucial Pro DDR4 RAM 32GB Kit (2x16GB) 3200MHz, Intel XMP 2.0, Computer Memory (PC) - CP2K16G4DFRA32A​

This has Intel XMP and im not running an intel CPU (Price of the ram is good though)

 

[rorton]

It’s a AMD Ryzen 7 2700 Eight-Core @ 3200 MHz

 

[rorton]

Why do you think you need an insane amount of RAM for a NAS? I assume you're using something like freenas so a lot less memory intensive than just having Windows etc

I’m running unraid

It’s not just a nas, I have a number of docker containers doing certain things and running a number of windows and Linux vms which is where the memory is getting used. Some of the vms need 8gb each allocated before they will run. Nas only as you say is not memory intensive

 

[rorton]

The memory controller of these CPUs is not the best, you might find it hard to run 4x 16GB sticks at decent speeds (I assume the Ballistix set is dual rank too).

I don't know what profiles the Crucial Pro sticks have available, but apart from the OC one, they're supposed to be able to run at JEDEC speed without XMP. Does your Ballistix set have a 2666 JEDEC profile?

If you rely on XMP/DOCP, it might work if you apply the Crucial Ballistix profile to the whole set, but it might not and I don't know how configurable XMP is on your board (e.g. if you can drop to 2400).

If XMP doesn't work and it reverts to JEDEC, it would depend what profiles each set have available, but in theory if they have a 2666 profile that could be used (albeit at slower timings than the Ballistix set is optimised for).

The safest option is usually to sell your existing memory and buy 2x32GB, though I'm not sure how your older CPU would do with these modules.

ASRock have a table on the page of your board and it looks like 2x dual rank and 2x single rank or dual rank is expected to achieve 2666 with Zen+ (Pinnacle Ridge).

I can't see support or optimisation for high density 16GB single rank or 32GB dual rank sticks mentioned in the BIOS updates.

Thanks for the reply. Certainly looks like not reusing the ram I have will be the best option.