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.

[Rodine]

Pass 1 at 8000 - 1 error 

[Silent_Scone]

That’s barely any coverage. This is why it’s best to use a more stringent OS based stress test such as Karhu.  

Memtest86 on DDR5 based platforms is good for checking for faulty DIMMs or making sure the system isn’t so unstable that it will corrupt the OS, but may only get you so far.

some pointers;

1. Active cooling can help when pushing things. Either a 120mm fan or an off brand memory cooler (RAM fan with the Encore)

2. Both VDD and VDDQ are ok to scale up to 1.6v, temperatures ideally kept at 50c or below to aid stability.

3. Tuning CPU System Agent and Memory Controller voltage is still the easiest method of dialling in stability on 14th gen. 

4. I would aim for a minimum of 4000% coverage in Karhu RAM test. 

[itsRichie]

Hi Rodine, nice to see you reached 8ghz and stable with the new dark hero MB/14900k! hoping it stays stable for you! i just purchased the newest dark hero MB. 

was wondering if you are running the

gpu at pcie gen 4x8 lanes with the T700 SSd in   M.2_1 slot @  nvme gen 5x8 lanes?

or is the ssd in m.2_2 running at gen 5x4 lanes? with gpu at PCIe gen 4x8 lanes? (is it no matter which configuration when using gen 5 m.2 nvme the 16 gpu lanes get clipped to 8 lanes? then could you use M.2 slot 2 for the T700 SSd running  backwards compatible at gen 4x4 with gpu at gen 4x16 lanes?

or is the only way to keep the GPU at full pcie gen 4 x 16 lanes to use one of the  the chipset M.2  nvme slots for the t700?

what an incredibly long question. forgive my lack of better words to shorten the question!   i am considering using the same configuration with dark hero, cpu 14900k, crucial t700  but i dont really want to run the 4090 gpu at 8 lanes and i think a gen 4 samsung 990 pro in m.2 slot 1 allowing gpu to stay at full 16 lanes would be a more efficient system than using the t700 at chipset  m.2 slot limiting its abilities... thoughts anyone

[Rodine]

X8 x8 when using gen 5 m.2 (m.2 would x4) in 1st m.2 slot 

the issue is with the cpu not the MB.

cpu doesn’t have enough pcie lanes to run gen 5 m.2 and graphics card at 16x at the same time. 

but, I doubt I will see much performance loss with my 4090 at 8x. Even if it is a few fps I don’t care about that. 

[optiman]

Thanks for all the replies.  I did not read up enough.  I can return one of the kits, so at this point just get what I have to the best stable that it can be.

@Nate152  I do have the 14900, and with everything set to Auto, cpu is running at 5800 and memory at 5600 already.  Thanks for the detailed instructions, but given I'm already getting 5600, would trying manual really help get anything faster?

[Nate152]

Yes, with the settings I listed, you should be able to go much higher than 5600MHz, 5600MHz is just the starting point for testing. 

I suspect you should at least be able to hit 7000MHz. There is a little more headroom with some voltages, depending how hard you want to push.

[optiman]

Giving this a try now.  I sent you a PM

[optiman]

trying Nate's settings, but it won't boot and the code on mb is 28, which is not in the manual.  Any idea what code 28 means?

@Silent_Scone  Thank you for your posts as well.  I will try Nate's first, but also yours to compare

[optiman]

found my mistake.  For timings, I set the PRE instead of ACT, thus why it wouldn't boot.  the error 28 must mean the problem is behind the keyboard 😞

running memtest at 5600 right now with Nate's settings.  If passes, will keep going up

[Nate152]

Awesome, keep us updated.

Silent Scone listed his voltages, his voltages will help you go higher with the Dram Frequency if needed.