Z370 extreme4 BSOD on boot

Hello,
Last week I built a new PC and had trouble installing windows 10 because I would get errors while installing. I eventually updated the BIOS to 1.3 and got the OS installed. The PC ran completely fine for about 8 days until today where it randomly froze with a BSOD and every time I try to boot it now I get a BSOD with the error "MACHINE CHECK EXCEPTION".

Hardware:
ASRock Z370 Extreme4 LGA 1151
I7 8700K
SAMSUNG 850 EVO 2.5" 500GB SSD
G.SKILL NT Series 16GB DDR4 2133
Cooler Master Hyper 212 EVO

I've been reading into it and found some similar problems some people had that were solved by changing some voltage settings on the UEFI. I tried this solution but it did not change anything. I am wondering if it's because of the memory speed (2133). If anyone has any idea of what could be wrong I would really appreciate some advice.

Thank you.

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Boose wrote: Well I decided to just mess around and try dropping the VCCSA VCCIO voltages. At first I dropped them to 1.07 and 1.01 and the PC got to the login screen before getting a BSOD. So then I dropped both down to 0.95 and now it seems to be fine. Does anyone know the optimal voltages I should be using for my ram type?

We need the full, exact model number of your memory from G.SKILL so we know what it is. For example, F4-3200C14-8GFX.

While this problem did not happen at first, you're saying that the default VCCIO and VCCSA voltages in the UEFI/BIOS cause the BSOD to happen with your memory?

Do you know what the default VCCIO and VCCSA voltages in the UEFI are?

You may be able to see what the VCCIO and VCCSA voltages are in the UEFI/BIOS, in the H/W Monitoring screen. If you click the Load UEFI defaults in the Exit screen, and restart into the UEFI again, that will reset them. You will likely just see Auto in their setting option, but look for them in the H/W Monitoring screen.

Or you can use a program like HWiNFO64 in Windows, and run its Sensor display, which should show VCCIO and VCCSA among many other readings.

Impossible to say what the optimal VCCIO and VCCSA voltages for any memory is, because that depends upon the memory controller (IMC) itself, that is part of the CPU. Your memory used with the older Kaby Lake or Skylake processors/memory controllers will need higher voltages than you need for both of those options. This could also be a slight memory compatibility issue.

One surprise with the Coffee Lake processor's IMC is how low the VCCIO and VCCSA voltages need to be compared to earlier Intel processors. That seems to be true for lower speed memory in particular.

Since most memory models are different, the only way to find the optimal voltages is to experiment as you have been doing. You should be able to reduce those voltages further to 0.90V or less.

One thing to check is if there is any difference between the voltage values you set in the UEFI, and the actual voltages read, both in the UEFI and Windows. Normally the actual voltage reading will be slightly higher than what its option is set to.

Default VCCIO is 0,95, VCCSA is 1,05.

But somehow Asrock increases it with certain RAM or XMP Profiles to something like 1,2 and 1,25.

I figure this much is needed for higher Frequencies, i even work 1,3 VCCIO, but it also seems that it can be too high for some CPUs/MB
So finding the sweet spot is difficult because there can be voltages too low or too high. And it determines which RAM speed youre able to achieve.

Afterall anything above 2600 RAM is overclocking.

In my case Asus increased VCCST too high for my System. The fact that Asrock does it automatic is a thing, but i guess its trying to make OCing simpler?? Im not sure

Well the problem is back now out of nowhere. This time giving me a BSOD after of few minutes of doing pretty much anything on it after booting up.

I'm starting to think I just went with the wrong RAM for this build.
Also this was after lowering the voltage on both as low as they would go (.90,.95)

Edited by Boose - 20 Dec 2017 at 11:38am

Boose wrote: Well the problem is back now out of nowhere. This time giving me a BSOD after of few minutes of doing pretty much anything on it after booting up. I'm starting to think I just went with the wrong RAM for this build. Also this was after lowering the voltage on both as low as they would go (.90,.95)

Your memory in not incompatible with your board. You can see that on its product page, in the QVL list:

https://www.gskill.com/en/product/f4-2133c15d-16gnt

The BSOD could be caused by something else besides those two voltages. Are you still getting the Machine Check Exception reason for the BSOD?

Is your memory in the A2 and B2 slots? Did you ever run a memory test on the memory, in case it has a problem? Did you ever reseat the memory in the DIMM slots? Are the timings and speed of the memory set to the values in the specifications? I assume you are running the memory at 2133, and 1.2V?