Random reboot on Sierra 10.12.6 - Z270i Strix - I7700K - Internal graphics

[sinclairfr]

Hello!

I built the Customac Mini Deluxe from the specs of October 2017.

Everything works fine but the system is unstable.

I am having random reboots on light loads and in 100 percent of the cases on heavy loads in MacOs Sierra 10.12.16 and also on a fresh HighSierra Install.

For exemple :

• Handbrake makes the system crash.
• Cinebench too.
• Photoshop sometimes.

To be noted :

• I am not getting crash reports in /System/Logs. This looks like a shutdown not a kernel panic.
• I am not overclocking the system and am running the vanilla install instructions I got on tonymac.

What I have tried so far :

• I tested the stability of the built on Ubuntu 16.
• Windows 10 runs smoothly.
• I ran MemTest and got no errors.
• I ran multiple benchmarking tools on Windows. Everything is producing normal results.

What seems to have an slightly improving effect :

• running on a single 16GB memory stick
• lowering the DDR4 frequency to 1866 in the bios
• disabling turbo mode of the cpu in the bios

Here is my hardware :

• Intel Z270i Strix Gaming
• I7700K - Internal graphics hd 630
• 2x16GB Crucial DDR4-2400 UDIMM PC4-19200 • CL=17 • Dual Ranked • x8 based • Unbuffered • NON-ECC • 1.2V
• Intel Stock CPU cooler
• SanDisk Ultra II SSD 480GB
• PICO PSU 150W
• Up to date bios

What I have suspected at first but eventually ruled out :

• I did suspect the RAM, but 1 hour and 10 minutes of MemTest ended with no errors
• I thought of a faulty/overload PSU but I ran stress tests in windows and it seems to hold strong.
• I also thought that he crappy Intel CPU cooler was the culprit but when I launch HandBrake or Cinebench the system reboots instantly, hence not because of the CPU running hot but because of something else.

I think I am stuck with a BIOS/Kext/Parameters tweaking problem here but I don't know what to do. I am getting desperate here...

Any help or clue would be greatly appreciated. Thanks a lot!

Enclosed : config.plist

 

[robinhuang]

Hello!

I built the Customac Mini Deluxe from the specs of October 2017.

Everything works fine but the system is unstable.

I am having random reboots on light loads and in 100 percent of the cases on heavy loads in MacOs Sierra 10.12.16 and also on a fresh HighSierra Install.

For exemple :

• Handbrake makes the system crash.
• Cinebench too.
• Photoshop sometimes.

To be noted :

• I am not getting crash reports in /System/Logs. This looks like a shutdown not a kernel panic.
• I am not overclocking the system and am running the vanilla install instructions I got on tonymac.

What I have tried so far :

• I tested the stability of the built on Ubuntu 16.
• Windows 10 runs smoothly.
• I ran MemTest and got no errors.
• I ran multiple benchmarking tools on Windows. Everything is producing normal results.

What seems to have an slightly improving effect :

• running on a single 16GB memory stick
• lowering the DDR4 frequency to 1866 in the bios
• disabling turbo mode of the cpu in the bios

Here is my hardware :

• Intel Z270i Strix Gaming
• I7700K - Internal graphics hd 630
• 2x16GB Crucial DDR4-2400 UDIMM PC4-19200 • CL=17 • Dual Ranked • x8 based • Unbuffered • NON-ECC • 1.2V
• Intel Stock CPU cooler
• SanDisk Ultra II SSD 480GB
• PICO PSU 150W
• Up to date bios

What I have suspected at first but eventually ruled out :

• I did suspect the RAM, but 1 hour and 10 minutes of MemTest ended with no errors
• I thought of a faulty/overload PSU but I ran stress tests in windows and it seems to hold strong.
• I also thought that he crappy Intel CPU cooler was the culprit but when I launch HandBrake or Cinebench the system reboots instantly, hence not because of the CPU running hot but because of something else.

I think I am stuck with a BIOS/Kext/Parameters tweaking problem here but I don't know what to do. I am getting desperate here...

Any help or clue would be greatly appreciated. Thanks a lot!

Enclosed : config.plist

If I remember it right, kernel panic logs are now kept in /Library/Logs/DiagnosticReports directory, not /System/Logs. Maybe you can check there.

 

[sinclairfr]

Yes, you are right, I do check all the usual locations for crash logs including the one you mentioned and nothing shows.
I believe I have to tweak the RAM settings in the bios in order to achieve system stability but I have not clue as to how I should proceed.

 

[sinclairfr]

I am dealing with a hardware shutdown but do I have to increase the voltages of my RAM/CPU or lower them is a total mystery to me.

 

[sinclairfr]

I will be partly answering my own question and I am sure this will help other:

Drastically reducing the RAM frequency in the bios stopped almost all the reboot occurrences.
The only problem is that I had to go from the factory rating 2400Mhz to 1333Mhz to achieve real stability, with the same 1.2v voltage.

At this setting, handbrake can complete a encoding to the full, photoshop runs, cinebench too, geekbench did crash at the end but that is a such a release already to have some improvement after 3 days of tinkering.
I am getting there.

One big problem and question remain : How come do I have to reduce the frequency so much in order to achieve system stability? If I chose to run at 2400Mhz, then do you guys think I should increase the voltage?

 

[sinclairfr]

Second update :

1. Inserting the second memory stick did bring back the random reboots on heavy load.
2. Lowering the Ram Frequency did not really improve things.
3. Going from 1.19v to manual 1.22v did get me to finish a Handbrake encoding until the end.

Yes, I don't really know what I am doing, I need advice from an experienced overclocker.

So far, all I can tell you is that Asus BIOS are absolutely horrible to understand and interact with, I used to have a Gigabyte Motherboard and the BIOS was so clear and intuitive. With Asus, you get overclocking features without even requesting it, it is so annoying.

Next step will be to try again if geekbench can complete.