Any difference between F5-6400J3239G32GX2-TZ5RK and F5-6400J3239G16GX2-TZ5NR?

[mich_ga]

Hello, I'm buying a new CPU and motherboard, specifically a Ryzen 7 7800X3D to be mounted on a Gigabyte X670 AORUS ELITE AXboard.
The board RAM compatibility list include these RAM modules: F5-6400J3239G32GX2-TZ5RK, while in a store I found an offer for those ones: F5-6400J3239G16GX2-TZ5NR. They look to be the same thing, even if the P/N code differs by the last two characters.
Do you know if there is any actual technical difference between the two?

Thank you!

[emissary42]

F5-6400J3239G32GX2-TZ5RK --> 32GX2 = 2x32GB kit (64GB overall capacity)
F5-6400J3239G16GX2-TZ5NR --> 16GX2 = 2x16GB kit (32GB overall capacity)

TZ5(R)(K/S/W) = Trident Z5 & RGB variants are XMP enabled for Intel platforms.
TZ5N(R) = Trident Z5 Neo & RGB variants are EXPO enabled for AMD platforms.

While there is cross platform compatibility via workarounds the motherboard manufacturers have implemented, the G.SKILL QVLs tell you what motherboards were tested and are officially supported.

https://www.gskill.com/qvl/165/374/1...2GX2-TZ5RK-QVL
https://www.gskill.com/qvl/165/390/1...6GX2-TZ5NR-QVL

Since the Gigabyte X670 Aorus Elite AX is not among the motherboards that are compatible with the F5-6400J3239G16GX2-TZ5NR, it is not very likely that you would be able to utilize the XMP of the F5-6400J3239G32GX2-TZ5RK. If the system fails to POST or is unstable, you might have to reduce the frequency or go with a manual overclock instead.

[mich_ga]

F5-6400J3239G32GX2-TZ5RK --> 32GX2 = 2x32GB kit (64GB overall capacity)
F5-6400J3239G16GX2-TZ5NR --> 16GX2 = 2x16GB kit (32GB overall capacity)

TZ5(R)(K/S/W) = Trident Z5 & RGB variants are XMP enabled for Intel platforms.
TZ5N(R) = Trident Z5 Neo & RGB variants are EXPO enabled for AMD platforms.

While there is cross platform compatibility via workarounds the motherboard manufacturers have implemented, the G.SKILL QVLs tell you what motherboards were tested and are officially supported.

https://www.gskill.com/qvl/165/374/1...2GX2-TZ5RK-QVL
https://www.gskill.com/qvl/165/390/1...6GX2-TZ5NR-QVL

Since the Gigabyte X670 Aorus Elite AX is not among the motherboards that are compatible with the F5-6400J3239G16GX2-TZ5NR, it is not very likely that you would be able to utilize the XMP of the F5-6400J3239G32GX2-TZ5RK. If the system fails to POST or is unstable, you might have to reduce the frequency or go with a manual overclock instead.

Thank you for your response!
What makes me very confused is that that mobo mount an AM5 socket for AMD Ryzen CPUs, and in the RAM compatibility list there is the TZ5RK, which I understand is for Intel platforms, but not the TZ5NR, which wuold be specific for AMD. Maybe I should go with something else like this F5-6000J3038F16GX2-TZ5NR....

[emissary42]

The motherboard manufacturers use a small selection of memory from each manufacturer that is available to them. It can result in qualifying combinations for compatibility, that don't really make sense, like two modules from a quad kit for a 2 DIMM / ITX motherboard. However testing XMP enabled kits is somewhat understandable, since they had to develop and verify their implemented workaround to apply the Intel standard on AM5.

At least for any G.SKILL product you can instead go by their own QVL. It might be more conservative, but also is more complete. In addition to that it guarantees compatibility beyond a single tested sample, for all kits of that type (and regardless of IC type).