Showing results for 
Search instead for 
Did you mean: 

4 DIMMs in ROG Maximus z790 Hero - no XMP

Level 8
The specs say that 4 DIMMS and up to 128 GB of RAM are a supported configuration on the ROG Maximus z790 Hero. The manual clearly shows that installing 4 DIMMs is allowed. I read it before I bought the motherboard.

I have purchased 4 DIMMS from the Qualified RAM list:
CMT64GX5M2X5600C40 (Ver5.43.13)

The version on my RAM matches the above.

With the RAM in slots 2 & 4, I can use both XMP I and XMP II profiles to achieve DDR-5600.
With RAM in slots 1 & 3 - I can POST ONLY with the 'auto' profile. Selecting the XMP profiles causes the following issues:
1) Ridiculously long POST times (several minutes)
2) Memory errors in Memtest86 - and is not possible to boot the OS

I have swapped all the RAM, so I know they all are working. The above 2 issues happen when using slots 1&3.

I expect a future BIOS update is coming to allow the use of slots 1&3, or do I have to RMA this motherboard because of bad slots?

My Configuration:
Asus ROG Maximus z790 Hero
4x32 GB Corsair 5600 DIMMs - CMT64GX5M2X5600C40 (Ver5.43.13)
Intel i9-13900K

If you are enabling XMP, that is a type of overclocking.  If you've already returned the entire system, it sounds like you bought it as a complete package from a systems integrator; you should have been pushing them for a solution.  Did you check to see if your specific memory part number was listed on the board's memory QVL?  Were you trying to run a 2 DIMM config or a 4 DIMM config, as one of your other posts seems to be saying 4x32.  4 DIMM DDR5 configs can be a bit of a challenge.  Did you try running the system on "load optimised defaults" (i.e. no XMP or other BIOS tuning) to see if it was stable without overclocking?