ASUS ROG Maximus Z790 Hero with 128GB DDR5 RAM

[pulse7]

Hello,

I have a brand new machine with the following components:
- CPU: Intel Core i9-13900KS
- Motherboard: ASUS ROG Maximus Z790 Hero (BIOS Version: 0703)
- RAM: 4 x 32GB G.Skill Ripjaws S5 DDR5-6400 CL32-39-39-102 (F5-6400J3239G32GX2-RS5K)
- SSD: 4TB M.2 NVMe Kingston KC3000 PCIe 4.0
- GPU: PNY GeForce RTX 4090 Verto Triple Fan 24GB
- Fan: Noctua NH-D15
- Case: be quiet! Silent Base 802
- PSU: be quiet! Straight Power 11 Platinum 1200W
- OS: Microsoft Windows 11 Pro 64Bit

NOTE: Since there were (almost) no available Quad 32GB DDR5 kits in Europe a few weeks back I bought two separate kits, each with 2 x 32GB DIMMs, with exactly the same properties/parameters, only the Manufacture Date is different (one pair is "Week 11/2023", another pair is "Week 14/2023").

I have a big problem: 128GB DDR5 RAM on this machine is not stable with default BIOS settings ("load optimized defaults", everything on auto, no XMP)! I see this in Prime95 Torture Test within few minutes as well as Windows and apps crashing and BSODs.

If I use just one pair of RAM (2 x 32 GB) in slots 2 and 4, and leave slots 1 and 3 empty, everything works stable even with XMP with 6400 MT/s! Also with another pair of RAM (2 x 32 GB) everything works stable! So both pairs of RAM are working correctly! But if I put both pairs of RAM (4 x 32 GB) in slots 1, 2, 3 and 4 the computer is unstable even with default frequencies! Note that this RAM defaults to 4800 MT/s in non-XMP mode and this is also the default BIOS frequency after "load optimized defaults"!

Even if I downclock the RAM to down to 3600 MT/s - which is the minimal guaranteed speed for all possible configurations:
https://edc.intel.com/content/www/br/pt/design/products/platforms/details/raptor-lake-s/13th-generat...

...I get errors with Prime95 Torture Test within minutes.

Note that BIOS shows me only one XMP I profile (6400 MT/s) even though I see a long list of memory timings in AIDA64 Extreme! So I have to set the frequency 3600 MT/s manually and hope that all other parameters (CL-RCD-RP-RAS) are correctly set in this case - since I don't know them all...

My question: What should I do to get a working computer with 128GB of RAM with this motherboard with default settings?

I guess you will say: you should use paired quad DIMMs. But which one should I buy? There is no Quad RAM on this motherboard's QVL:
https://rog.asus.com/motherboards/rog-maximus/rog-maximus-z790-hero-model/helpdesk_qvl_memory/

...and there are only two available now in Europe: https://geizhals.eu/?cat=ramddr3&xf=15903_DDR5%7E253_131072%7E256_4x

- Kingston FURY Renegade Pro RDIMM Kit 128GB, DDR5-5600, CL36-38-38, reg ECC, on-die ECC (KF556R36RBK4-128)
- Corsair Vengeance RGB black DIMM Kit 192GB, DDR5-5200, CL38-38-38-84, on-die ECC (CMH192GX5M4B5200C38)

If I buy one of these and it will not work with default settings (no XMP) - what should I do next? I guess the support here will say: it is not on the QVL list... and in this case I ask myself - why did I buy this motherboard? It is written, that it supports 128GB RAM, but there is no 128GB RAM on the QVL list...

Can anyone here tell me how to get 128GB on this mobo? I need exact DDR5 RAM model name and manufacturer...

Will upgrade to the latest version of BIOS (0904) make my system stable with the default settings (no XMP)? Will I see all available XMP profiles displayed in BIOS?

Or should I send back this mobo and RAM and buy a DDR4 motherboard where there are plenty of 128GB RAMs on QVL lists and everything costs much less and is much more stable?

This mobo wasn't cheap and 128GB DDR5 RAM wasn't cheap - so please help me resolve this issue in the best possible way...

Sincerely,
Mark

[pulse7 · Accepted solution]

Update: I was able to stabilize 128GB DDR5 on my new machine!

For everybody with the same problems - here is what I did:

1. I removed 2 DIMMs to have stable machine with 64GB DDR5 only (I removed DIMMs from slots 1 and 3). NOTE: I had to click on a new Q-Release button to release the GPU in order to remove one Noctua CPU fan above RAM in order to remove 2 RAM DIMMs!
2. Then I updated the motherboard BIOS to version 0904 (my ME firmware was already up-to-date).
3. After checking the new BIOS version in BIOS I inserted back 2 DIMMs so all 4 DIMMS were populated (2x32GB).
4. Next I cleared CMOS with "Clear CMOS" button to clear all old settings/trained data.

After doing this, my memory was stable at default 4800 MT/s speed (without XMP) and also with 5200 MT/s (XMP speed). I tested my machine with Prime95 Torture Test for 48 hours at 5200 MT/s to ensure that the system is stable!

[Tiggere5]

Thanks for the great info. Sorry if this is a silly question but how did you clear the CMOS. I haven't had to do it before and I want to make sure I follow the same process you did. 

[Murph_9000]

For boards which don't have a clear CMOS button:

How to clear CMOS?

[pulse7]

Here is the info on how to clear the CMOS: https://www.asus.com/support/FAQ/1030210/

My board has the "Clear CMOS" button on the backside. So I followed the steps under C: "There is a CLR_CMOS button attached to the motherboard I/O. Please press this button when shutting down and unplugging the power cord. After reconnecting the power and booting, press and hold the delete key or F2 key to enter the BIOS to reset."

To be clear:

1. Turn off your computer and disconnect the power cord.
2. Press the "Clear CMOS" button for a few seconds.
3. Reconnect the power cord and turn on your computer and at the same time hold the "Delete" key (or F2 key) to enter the BIOS to reset.

[Tiggere5]

Thanks I found the button. I ran the MemTest86 (v10.0) that was included in the tools tab of the BIOS and still get 1 error. I attach photo for reference incase anyone knows what it means and/or how to fix it. 1 is way better than the 800+ but not sure if the one will mess everything up. Did you get an error or try to run it? Thanks again for all.your help! 

 

[pulse7]

Try to run MemTest86 on each DIMM stick individually - using just one slot (please see the motherboard manual which slot you should use in case of just one DIMM stick; on Rog Maximus Z790 Hero this is DIMM_A2 1st slot which is the 2. closest slot to the CPU). Each DIMM stick must work individually with default BIOS settings (after clearing CMOS). If this is not the case you have defective DIMM stick which you should return. If you bought paired DIMM sticks, you should return/replace both DIMMs in this case (becuase you need paired DIMMs).

If each DIMM stick passed the MemTest86 test on default frequency, put 2 paired DIMMs into dedicated slots (consult motherboard manual again; on Rog Maximus Z790 Hero this are DIMM_A2 1st and DIMM_B2 1st whic are the 2. and 4. closest slots to the CPU) and run MemTest86 again - with default settings. This should work if DIMMs are not defective, because 2 DIMMs should not be a problem.

How many DIMM sticks do you have? Did you bought them all paired?

[eemmenis_za]

Still working without BSOD?  - You are lucky, mate.  I hope this becomes less tedious in future releases of the BIOS

[pulse7]

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@eemmenis_za wrote:

Still working without BSOD?  - You are lucky, mate.  I hope this becomes less tedious in future releases of the BIOS

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Yes, still without a single BSOD since motherboard BIOS upgrade to version 0904.

I am running it on XMP I profile with 5200 MHz (see attached screenshot of Windows Task Manager).

[cleiielc]

Puls7

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