MAXIMUS Z790 DARK HERO - i9-14900K - G.SKILL Trident Z5 XMP 3.0 DDR5 8000MTs - can't use XMP

[optiman]

My setup listed in the subject.  I updated the bios to 506 and I still only get 5700 MHz with my cpu when native is 6.0 GHz for this processor.

Everything is set to default / Auto.

My memory (F5-8000J4048F24GX2-TZ5RS 96gb) should run at 8000 MT/s using XMP profiles, but only running at 4700 MHz with AI Overclock Tuner set to Auto.  If I try XMP 1 or 2, it won't boot and restarts in Safe mode.

I wanted to see if anyone else is having these issues before I start trying different voltages / timings.

I was going to try manually setting the memory freq to 8000 and CL40-48-48-128 1.35V, which is what G.Skill advertises for my memory.  Not sure what to try for the cpu to get that at least at 6 GHz, and I was hoping to be able to OC higher.

Other hardware includes AIO Asus water cooler, Gen5 M2 and Strix GeForce RTX 4090 Gaming.

I want to take it slow so not to damage anything, thus posting here for some advice.

UPDATE:  Do not buy the Dark Hero, several have returned it because unable to get stable OC.  Instead, buy the Apex Encore and Corsair memory.

[Silent_Scone]

Hello, you need to remove one of the memory kits. Combining memory kits is neither supported or recommended by the memory or motherboard vendor. Remove one kit and retest. Populating all slots on a 2DPC board and hoping to achieve 8000MT is simply asking too much of the CPU memory controller. Moreover, the memory vendor has not binned the kit to be used in conjunction with another memory kit.

The 14900K has a maximum all-core Performance Core frequency of 5.6GHz. Anything above this is considered an overclock. 6GHz is the maximum turbo frequency and is only applicable to single-threaded workloads. Most CPUs will not be able to achieve an all-core P-Core frequency of 6GHz without exotic cooling or direct die.

https://www.intel.com/content/www/us/en/products/sku/236773/intel-core-i9-processor-14900k-36m-cache...

[Nate152]

Hello optiman

Did you make a typo with your memory kit or are you combining two 48GB memory kits?

 If you're combining two memory kits, this is why your'e having issues. Try with one memory kit (2x24GB) in slots A2 - B2 (2nd and fourth slots from the cpu).

This is what you listed - F5-8000J4048F24GX2-TZ5RS 96gb

[optiman]

Yes, I had two kits installed.  I removed one and now my cpu is at 5800 and my memory is at 8000.  Memtest fails with errors with either xmp 1 or 2.  Errors after only a minute or two.  sticks in A2 and B2.

Set AI Overclock Tuner back to Auto, now cpu is 5800 and memory is 5600.   Running memtest again and so far no errors.  Will report back later.

That said, how can I run at 8000 with either xmp 1 or 2 without errors?

btw, ran memtest before with both kits, of course slower speeds but without any errors.

[rulik006]

Z790 Hero is not able to run even ONE 2x24 kit at 8000 with 99% of cpu's
did you read G.skill QVL? 8000 compatible only with 2-dimm boards Apex,Tachyon, Dark

[itsRichie]

in the specs he provided, he says his

MB is a "DARK" 

ASUS Rog MAXIMUS Z790 DARK HERO

[Silent_Scone]

Few things to keep in mind.

1. 5200MT is the stock memory frequency for 1 DIMM Per Channel Configuration on 2 Slot Per Channel boards on 13th and 14th gen CPUs. Anything over this can be considered an OC.

2. 8000MT on a 2 DIMM per Channel board such as the Dark Hero may require some massaging of voltage and memory subtimings. In some cases, the CPU IMC will be the limiting factor.

3. VCCSA (System Agent) granularity means that an individual CPU may be more comfortable running at a higher or lower voltage than what is determined as a worst-case scenario by the auto rules. You will need to attempt tuning this manually. For example, for 8400MT my 13900KS requires 1.38v VCCSA in order to achieve stability.

4. The MCVDD (Memory Controller Voltage) Values between 1.4 and 1.6v typically for the frequency we're trying to achieve. What value depends on the CPU sample.

5. VDDQ and VDD should not need to exceed the predetermined XMP values, however, applying more voltage may help if other rails are not sufficiently tuned.

6. Evaluate subtimings, relaxing tertiary timings can help on CPUs with less capable memory controllers.

7. Decrease memory frequency from 8000MT until the system is able to pass memory stress tests.

Feel free to try my 8200MT profile @ 8000MT (120mm Fan)

VDDQ 1.51v
VDD 1.62v
IVR [Auto] 1.4v

VCCSA [Auto] 1.3v

MC VDD: 1.43v

[Nate152]

As rulik006 mentions, it's going to take a good cpu to be able to hit 8000MHz. I see you're using the 13900KS which is a good cpu, although the 14900K would likely have a little stronger memory controller.

Instead of using X.M.P., try setting your ram manually, I see your memory kit is rated at 1.35v so you have a little bit of headroom with the voltage.

I was helping a fellow in a similar situation, he was happy to get his 128GB ram kit to 5600MHz.

Solved: Re: ROG MAXIMUS Z790 HERO Vs DDR5 Vengeance 4x32G... - Republic of Gamers Forum - 969680 (as...

I list the same steps in that thread, but I'll list them here too. Grab a pencil and a piece of paper.

In the bios on the Ai Tweaker page...

1) Reset the bios to defaults - F5 key.

2) Set the Ai Overclock Tuner to Manual.

3) BCLK Frequency: Dram Ratio - 100:100

4) Memory Controller: Dram Frequency Ratio - 1:2

5) Dram Frequency - 5600MHz

6) Dram VDD voltage - 1.40v

7) Dram VDDQ voltage - 1.40v

8: CPU System Agent voltage - 1.275v

At the bottom of the Ai Tweaker page click Advanced voltages:

9) IVR Transmitter VDDQ voltage - 1.40v

10) Memory Controller voltage - 1.40v.

11) Dram Timing Control:

 At the top, set the primary Timings like so:

40

48

48

128

Command Rate - 2N

12) F10 and Enter to Save and Exit.

If it boots at 5600MHz, you can slowly work up the Dram Frequency a step at a time until it becomes unstable, then back it down a step.

How far are you able to get with the Dram Frequency?

[Rodine]

Nate you are awesome 

I have Z790 Dark, 14900K, Gskill 8000 48GB kit (24x2) used PN# from Asus Memory Support list. 
13 fans - x9 140mm, Corsair H170i, Thermalright contact frame. 

Asus RTX 4090 Strix OC, Crucial T700 gen 5 M.2 

been pulling my hair out trying to reach 8000.

i have been through 5 ram kits so far. 

until I stumbled on your recommended settings 

Currently watching memtest so far no errors at 90% +24% at 8000! Fingers crossed it holds… 

[Rodine]

Crap! 1 error at 90%+31% 

#%*! 

not sure what to tweak next any suggestions been sitting here for hours with this thing