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Unable to use all 4 DIMM slots

Level 7

Hello Community,

I am facing a problem with my RAM configuration and am hoping for your help and advice. My system consists of the following components:

MB : ASUS ROG STRIX B650E-F Gaming WiFi (90MB1BQ0-M0EAY1)
CPU : AMD Ryzen 7 7800X3D
RAM : 2 kits G.Skill TridentZ5 neo RBG AMD EXPO (F5-6000J3038F16GX2-TZ5NR) = 4 modules x 16 GB DDR5-6000

I am having trouble getting all 4 RAM modules to work together. When I have installed all 4 modules, the PC does not boot completely. Sequence is:
- LED Orange: RAM Test
- LED Red: CPU Test
- LED White:
- LED ORANGE: RAM error!

I have already taken some steps to solve the problem, but so far without success.
Here are the measures I have already taken:

Compatibility check: the RAM kits are compatible with the motherboard in configuration 1, 2 and 4 modules - Source: ASUS website for the MB ROG STRIX B650E-F Gaming WiFi

BIOS update: I have installed the latest BIOS update for my motherboard (1807 - Nov. 18, 2023)

UEFI BIOS settings: - EXPO: Enabled - (no further settings made)

Single test of RAM kits: only 1 module or 2 modules installed -> work perfectly.

Despite these efforts, the problem persists. As soon as I install both RAM kits (4 modules) together, the PC does not boot completely.

Thank you very much for your support!


Level 8

Im currently dealing with this too. Same memory and mb, but a 7950X3D.

No fix yet. I managed to get 4 sticks to work, but it straight up refuses to run with EXPO.

Starting to think that I might have to return them and just go with 2 sticks. (even if QVL says that it should work)

Super Moderator


Combining and mixing memory kits isn't supported by memory or motherboard vendors. This is because memory vendors bin and validate the memory kit in the density in which it is sold. If you combine memory kits, the overclocked settings in which the kit is validated for XMP/EXPO are no longer valid. You would need to return one or both of the memory kits and purchase a single kit validated for the density and frequency you are trying to run.

13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Thanks for clarifying that anyways. I guess I shouldve known. I guess  I was just lucky that it was working before I had to rma one of the kits. Will make sure to get a kit of two from the QVL list.


Are you stating that 2 identical kits (even same manufacturing date) do not work together? How then the ASUS memory compatibility table lists that exact product as compatible for 1, 2 and 4 slots?

  > G.SKILL F5-6000J3038F16GX2-TZ5NR 2x 16GB EXPO 6000 6000 SS SK Hynix 30-38-38-96 1.35 1,2,4

For selecting the memory I relied on that information.

I'm checking internally about the validation list. It'd be extremely rare that the team that does the validation would combine two separate kits.

13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Level 9

AFAIK, you cannot use 2 2x16gb kits and expect them to work at 6000mhz. The QVL lists 2x16gb kit at 6000mhz as compatible. But that does not mean you can put 2 kits in there.
If you want to occupy all 4 slots, you must buy a 4x16gb kit. You will notice that the 4 sticks kit will be validated for much lower clocks.

Thank you JronMasterR, it looks like not having a good enough understanding of how this all works as bitten me in the back side. My two kits are the same part number but bought from different vendors. Worked great with EXPO I & II with just two sticks, but with four sticks it's a no go with EXPO.

G. Skill Flare X5 32 GB (2x16), F5-6000J3038F16Gx2-Fx5, DDR5-6000, CL30-38-38-96 1.35v

I was hoping there would be some kind of work around for this issue but so far I haven't found anything posted.

Since I'm not a gamer, mostly use this new built for virtual machines, running in AUTO works with four sticks so I might just use it that way. Not sure if there would be a noticeable performance issue since I'm not gaming? Your thoughts if any would be appreciated.

Cheers, PB

ASUS ROG Strix X670E-E Gaming WIFI ATX AM5 / AMD Ryzen 9 7950X 4.5 GHz 16-Core

G. Skill Flare X5 32 GB (2x16) / F5-6000J3038F16Gx2-Fx5 / DDR5-6000, CL30-38-38-96 1.35v

You won't find any "workaround" as there is no magic bullet. Memory kits aren't designed to be combined. 

Getting combined kits working can require a level of memory overclocking that isn't easily understood or digested in a single post. Best to return one kit or both and purchase a memory kit in the density you wish to run - alternatively, run the kits at stock.

13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Thank you Silent_Scone for your reply. For the time being I will just leave the BIOS setting at AUTO since all four sticks work at that setting. Like I mentioned, I'm not a gamer so maybe it's not important for me to use EXPO for the way I use this PC.

Cheers, PB

ASUS ROG Strix X670E-E Gaming WIFI ATX AM5 / AMD Ryzen 9 7950X 4.5 GHz 16-Core

G. Skill Flare X5 32 GB (2x16) / F5-6000J3038F16Gx2-Fx5 / DDR5-6000, CL30-38-38-96 1.35v