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.

[optiman]

up to 7600 on pass 2 🙂

[Silent_Scone]

Hello,

As you increase the frequency, test stability with Karhu RAM Test or TM5 as Memtest86 may not pick up the majority of errors depending on the stability margin.

If you've applied a manual MCVDD (Memory controller voltage) suggested by Nate, note this value may need to be increased.

Lastly, remember to check out the MC SP Test located under the AI Tweaker page as this will give you a rough indication of the strength of the CPU memory controller.

[optiman]

Thank you Silent_Scone!  I appreciate your help and suggestions.

Which is best, Karhu or TM5?  I will get one and do as you suggested.

As for testing, I'm testing 7800 with memtest right now, 7600 was good.  I did try 8000 and got errors right away.  That said, I have not tried increasing the MCVDD voltage yet.  It's still at 1.40v

[Silent_Scone]

Hi,

I always use Karhu, one or the other is sufficient enough to establish stability.

[optiman]

Update, 7800 passed memtest.

mc sp test is 78

I haven't installed any OS yet, so I've been trying to sort out how to run Karhu from a bootable usb - suggestions?

I'm ready to try 8000 again, so I was thinking of changing the MCVDD to 1.43v and trying again

[Rodine]

[Silent_Scone]

Just to bring an example to the table here when on the fringes of stability of what constitutes a pass or fail.

8533MT 2x24GB in Memtest86 - 1 Pass successful 43 Minutes

Same preset in Karhu RAM Test

Error in under 5 minutes.

[Rodine]

I have been building PC's for years, I am somewhat familiar with overclocking but admit I am no expert. I have never really dabbled in memory OC until recently when they announced the Dark Hero. I read the specs and noticed support for 8000 Gskill and decided to start learning about memory OC. I stumbled on this thread and with the information shared from everyone within this community conversation I have found more success than I was able to elsewhere. Although still have a ways to go for stability I did also notice In AIDA64 my Read speeds were faster than my Gskill 6400 kit but everything else seemed slower... the latency was way slower at 8000 with current settings, sitting around 70ms... where the 6400 kit stock was around 59ms... So I a learning that faster does not necessarily mean better... There does not seem to be much of a gain in read/write and latency going from 6400 to 8000 unless that will get better with tweaking and more stable settings...

[optiman]

trying to get 8000 to pass, but still getting errors.  Here is what I have so far

Dram VDD will not let me set to 1.5, comes back at 1.435

VDDQ same, won't let me go past 1.435

System Agent = 1.38v

Memory controller voltage = 1.5v

I get errors with memtest right away.  I think it's because I'm unable to go higher on VDD and VDDQ.  Could this be realated to the jumper on the mb?  I read somewhere that I might have to change a jumper to go higher on cpu voltage.

[Rodine]

You have to unlock high power memory setting drop down right above 

be careful because the memory voltages then change to 2.0v in red but your changing them with the settings provided previously.