System won't boot with DDR4 3000mhz

ArkaNx

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May 13, 2012
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Hello, my build is an ASRock Z170 Pro4s, Core i5 6600k, team vulcan 3000mhz (2x8gb), hyper 212 evo, evga 500B psu. With the BIOS updated to the latest 7.0 version, without changing anything in the BIOS settings, the memory runs at 2133mhz 15-15-15-36 @1.2V. The problem is that this memory should run at 3000mhz 15-15-15-35 @1.35V. When I load the XMP profile the system doesn't boot. I've tried OC'ing manually the memory without OC'ing the CPU, but by setting the timings manually to 15-15-15-35 @1.35V I could only push the memory to 2666mhz stable without the OC on the CPU. I, then OC'd the CPU to stable 4.4ghz at 1.3V Vcore and that made me able to get the memory up to 2900mhz without any crashes. I'm kinda worried about getting the CPU even higher with an air cooler, but I really want my memory to run at the rated speed. Should I OC more my CPU or there are any other adjusts to be made?
 

Rogue Leader

It's a trap!
Moderator


Bumping up the CPU voltage many times is needed to allow memory to run in its XMP mode for anything over around 2600mhz. As long as your temps are good you can push it more with that air cooler, its worth a try.
 

Quaiden

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Sep 27, 2014
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Have you tried removing 1 of the 2 chips and enabling the XMP. If it works swap the chips and try again. If they both will clock to XMP profile individually you may have an issue with motherboard. If neither will clock up then I could call your RAM defective. I am guessing you have 1 bad chip out of the two... testing them individually will tell you which one is the problem. Since they are a pair you should exchange them for another pair once you have confirmed you have a bad chip.
 
Are you sure the timings are 15 and not 16?

In which slots did you install the RAMs?

Did you load the default settings after updating the BIOS?

edit: Funny thing I just discovered, ASRock doesn´t officially support 3000MHz:
"Supports DDR4 3866+(OC)*/3600(OC)/3200(OC)/2933(OC)/2800(OC)/2400(OC)/2133 non-ECC, un-buffered memory"
just kidding ;)
 

ArkaNx

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May 13, 2012
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Hello,
after testing the memory sticks individually by resetting the bios, enabling the XMP I've got this results.

https://postimg.org/image/oxk6g4wab/
https://postimg.org/image/afmz854z7/
https://postimg.org/image/s6ylmlkdv/

So, the memory sticks are fine when being used individually, they can easily reach the rated speed and timings. The problem only happens when I insert both sticks at the same time. I've tried A1-B1 and A2-B2 slots.
 

ArkaNx

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May 13, 2012
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No luck. The DRAM voltage when going up 0.05 (1.4v) was red, so I went up only to 1.39v. the VCCIO was at 0.95v so I changed it to 1v.

 

ArkaNx

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May 13, 2012
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Didn't work. Also, I couldn't change the command rate from Auto.
 

Tradesman1

Legenda in Aeternum
Start with one stick under XMP and raise voltages as indicated above, may well need an OC on the CPU as well, the MC (memory controller) in the CPU is needing help for 2 sticks. Also if you do find Command rate - leave it at 2T, 1T is for more performance and more strain on the MC
 

ArkaNx

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May 13, 2012
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What are the "safe" voltages that I can go for on VCCIO, DRAM and VCore?
 
Well - everything is great there. Congrats.
xmpenabled1mem.jpg

I'd try to get 1T command rate. But it's not such a big deal.
 

ArkaNx

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May 13, 2012
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This result is for one stick at a time, they are both ok, running at XMP profile. When I stick both at the same time and select the XMP profile, the system doesn't boot. I'll try what Tradesman said, but I won't go "red" on voltages. It feels like the timings are perfectly fine but the memory sticks aren't receving voltage enough to reach the 3000mhz with both sticks on. I don't think that anything is defective, for me it's just lack of voltage on the memory sticks.
 

ArkaNx

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May 13, 2012
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I left the DRAM voltage at 1.4v and kept doing increments of 0.05 on VCCIO. The VCCIO eventually got stuck at 1.2v and still, had no success. Any other ideas?
 

ArkaNx

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May 13, 2012
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Since I had to reset the BIOS a couple of times, I May have forgotten to oc the processor again. I'll do the oc First, boot into Windows, check the stability for at least 30min and then proceed to bump the voltages as I did previously, but I did with the processor at stock.
 

ArkaNx

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May 13, 2012
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Hello again :)

So, after getting the OC stable at 4.4ghz (tested for 30min) I've set the timings to 15-15-15-35 and set the DRAM voltage to 1.4v and went all the way up to 1.2v at VCCIO and yet, didn't work. Maybe there is something else wrong. I've read something about the LLC, VCCSA but didn't try any of that. What bothers me the most is that when I plug a single memory stick the only thing I have to do is set the XMP profile and it runs buttery smooth.
 

ArkaNx

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May 13, 2012
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So, after fooling around with the memory slots, I figured something out. Whenever I insert any of the two memory sticks on slots B1 or B2, the XMP profile won't load. However, when I insert any of them on the slots A1 or A2, the XMP profile loads like a charm. Are slots B1 and B2 defective in some way? Memory sticks are perfectly fine, I've tested many times, they load perfectly when inserted on slots A1 or A2. I hope anyone can figure this out!
 

Tradesman1

Legenda in Aeternum
That narrows things down a bit, sounds like a channel problem - couple of normal problems are the CPU cooler is too tight in a corner or side which can throw the CPU out of level and affect the MC, since most people tend to overtighten coolers, can try loosening and then just snug down screw tight. Then try the DRAM in A1-B1 or A2-B2. The other common problem is bent/broken pins in the CPU socket