TUF Gaming Z790 Plus WIFI and Kingston Fury: no XMP possible?

[steveduemile]

Hello to everyone!

Something strange is happen to me.

I decided to upgrade my rig and i choose an Asus TUF Z790 Plus WIFI, a brand new Intel i9 14900K and, for the RAM, Kingston Fury 32x2 gb 6400MT/s DDR5 CL32 KF564C32BBAK2-64 (wich are Asus VQL)

When i tried for the first time to boot the rig (with no other vga except those onboard) i mounted the RAM in slot 2 and 4: no POST. First strange thing!

Then i tried one by one and found that in slot 3 and 4 the RAM work regullary.

I activated the XMP profile and they work , as per specification, at 6400MT/s.

Then i updated the BIOS from version 1663 to 1805. and here starts the problems: the RAM in plug and play speed (4800MT/s) works but with XMP1 and XMP2  is not possible to complete the POST.

The i tried other two kind of RAM (always Asus VQL) : Corsair Vengeance 7200MT/s CMH48GX5M2B7200C36 and Corsair Vengeance 6000 CMK64GX5M2B6000C40W  but with the same results.

I also changed the MoBo with another Asus TUF Gaming Z790 Plus WIFI  with the same results: with BIOS ver 1663 all XMP profile works, with BIOS 1805 no.

So, i tried to rollback BIOS to 1663 but no results: the Kingston RAM does not work with XMP1 or XMP2 profiles.

I've contacted also the technical support and the told me the the fault is about the CPU (defective one), but the CPU in a MSI motherborad works regularry with RAM in XMP mode, both 1 and 2 version.

Now i am thinking to change the CPU , but before i try to find some help here....

Thank you for your attention, hoping someone can help me!

[Silent_Scone]

Hi @steveduemile 

Considering you've tried multiple memory kits, it would seem that the memory controller is likely on the weak side. Board auto rules  vary from vendor to vendor which can account for certain kits working on one board to the next without manual tuning depending on how relaxed the memory subsets are (but there are other permutations to account for also)

Firstly try:

The correct slots for two DIMM configuration is A2 and B2.

If using a CPU contact frame, remove and reinstall the stock retention mechanism. Inspect the CPU socket and pin pad and ensure not to over-torque the CPU cooler as this can impede overclocking range.

Set XMP 2

Raise tCAS by 2 clocks

Increase VDD/VDDQ by 30-40mV

Try reducing DRAM Frequency till the system is able to complete POST

[steveduemile]

Hello Silent_Scone,

thank you for your answer, is very appreciated.

As i already said the RAM module in A2/B2 does not works. Works only in B1/B2 and i think this is a very strange thing.

I do not use contact frame but i will try your suggestions.

Thanks again.

[Silent_Scone]

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@steveduemile wrote:

Hello Silent_Scone,

thank you for your answer, is very appreciated.

As i already said the RAM module in A2/B2 does not works. Works only in B1/B2 and i think this is a very strange thing.

I do not use contact frame but i will try your suggestions.

Thanks again.

---

This is precisely why I've suggested what I have, as it could indicate poor pin-pad contact. 

[steveduemile]

Here we are....

i tried evrything you said.

Pin pad seems perfect.

CPU temp in BIOS 32 ,in Windows 28/41

I tried slot A2/B2 no POST.

I tried evry single combination, no POST except B1/B2.

Tried your instructions about tCAS, VDD, RAM frequency etc: no POST.

Only one thing has changed: if i use only B2 slot with one module 32giga it's works and i can use the pc with RAM at 6400 MT/s., no matter if Kingston or Corsair (at 7200 MT/s and  6000 MT/s, depend form the module.)

Any idea? Thank you very much for your help, really.

I think that tomorrow i will order another I9 14900K and.....pray!

Thanks again.

[steveduemile]

CPU changed with another I9 14900K: again, no XMP possible.