Skylake hard locks seeminly when IDLE / CStates ON

[GGlyn]

Myself and others have been struggling with a different hard lock problem with Skylake and we have ran out of options but to assume it is a CPU fault/issue. Does anyone have any comments or feedback?

The long thread is over here, but I will summarise. http://www.tomshardware.co.uk/forum/id-2830772/skylake-build-randomly-freezing-crashing/page-7.html New Skylake Build Randomly Freezing/Crashing - Page 7 - windows 10 - Windows 10

Our systems hard lock randomly but appears on the most part to be when IDLE or next to IDLE. The hardlock can come when playing video, browsing (reading) or mostly when not interacting at all. Some (like myself) noted that they seem to occur more often if you are doing a large amount of disk IO (partition move for example or copying 40+ GB of data disk to disk).

Hard locks happen in either Windows (7,8,10) or Linux.

With CStates on, the crashes are often and usually within 10 minutes of IDLE. With CStates disabled completely most find that the system remains "mainly" stable for days. Generally, no one has reported locks when gaming or under high CPU load (so I do not think this is the Prime95 example but then, since compilers / drivers use the latest instructions (according to CPUID) I cant be sure).

The symptoms happen on many different manufacturers motherboards, RAM types and setups. We have successfully removed or replaced all components and the only change that seems to make a difference is CPU for a few. CStates off in the BIOS is absolutely a guarenteed way to stabilize significantly but not fix.

I changed CPU (after trying everything else) and find it now mostly stable with CStates ON. I must be clear that my system is 100% identical, CPU # 1 crashes all the time and must have CStates off, CPU # 2 does not crash so often even with CStates ON. One may argue this is a problem with my PC, a fault, but with so many people having the exact same issues I cant believe it is a defect. And with Cstates/SpeedStep so specifically (a known new part of Skylakes architecture), I remain convinced that this is something real.

Others were not so lucky, a replacement CPU did not make the situation better. Batches from different factories as well etc etc

My new CPU has hard locked but not when IDLE like the last one (not yet anyway). Mine can lock when under full load, video transcoding, but not more than 1 in 10 sessions. Cstates ON seems equally stable on this CPU as OFF.

Thanks for any suggestions you can give.

[satas]

you are right Ronin, I just wanted to give GordonW some generall information about BugChecks.

I'm glad you don't have any issues with the motherboards, recent information makes it likely that I'm also facing compatibility issue instead of faulty component.

Asus seems to be really a story on it's own, the forums just come and go as they wish.

although the user there help much more than Asus support itself.

[MBell11]

Hello everyone,

I have been experiencing this hard lock issue since I built my new PC last february, the computer freezes completely and I have to use the power button to turn it off, even the restart button does not work.

Here's my PC :

Asus Z170-k motherboard (with the latest bios)

Intel core i7 6700k (microcode 74)

2 x 8 GB DDR4 G SKill Ripjaws V 3200mhz (downclocked to 2666 mhz for now)

MSI Geforce GTX 980Ti Gaming 6G

Corsair Rm750x PSU

2 Samsung SSDs, 2 HDDs

Windows 10 Pro

Oddly, I had first bought an Asus Z170P-D3 with DDR3L memory, which I only used for a week, and I did not have any freeze.

Then I changed my mind and chose to go for DDR4, and that's when the first hard lock happened.

I tried a different PSU, graphics card, different DDR4 sticks (HyperX Fury 2666), in vain. I ran all the RAM tests without any issue, tried with XMP enabled, disabled, etc...

I also checked my CPU as I was worried it could be bent, but no issue there. My temps are perfectly fine, my drivers are up to date.

The hard locks happen very randomly, but it happens mostly when watching videos, listening to music, moving files, downloading files... Which led me to even consider an HDD issue, since faulty HDDs / SATA cables, or faulty motherboard SATA ports can lead to hard locks.

I don't know if it's related, but I almost always get a hard lock when I'm tweaking the PWM fan settings in the BIOS... Other than that, the BIOS is perfectly stable.

I installed the latest bios on March 15th, had a lock on the 28th, and then no lock until April 24th (so 4 weeks without any problem). So it seems my system is more stable overall now, but I don't know if it's due to the BIOS update, or the new microcode or something else...

What's really frustrating is not knowing the exact cause, I would not want to RMA my motherboard or CPU for nothing...

Last thing I tried as of today, as seen in a similar thread : disabled fast boot in both Windows and in the BIOS, it solved a few people's problems, but I don't know why it would prevent the random freezes.

[satas]

that's very similar to my issue Berdugo.

what's the BugCheck error code after you get a freeze?

[MBell11]

When I get a hard lock, nothing happens and I have to manually turn off the PC, how do I check the error code ?

In the event viewer, I have this :

-System-Provider[ Name] Microsoft-Windows-Kernel-Power[ Guid] {331C3B3A-2005-44C2-AC5E-77220C37D6B4}EventID41Version3Level1Task63Opcode0Keywords0x8000400000000002-TimeCreated[ SystemTime] 2016-02-19T19:48:11.246330900ZEventRecordID348Correlation-Execution[ ProcessID] 4<td nowrap="nowra...

[satas]

@ Berdugo

you can download the BSOD viewer to see a bit more what's going on.

current version is v1.55:

http://www.nirsoft.net/utils/blue_screen_view.html Blue screen of death (STOP error) information in dump files.

please don't delete any log or dump files. are your dump files enabled at all in Windows?

if not here is a very good step by step description how to do it, thanks to Tenforums :

http://www.tenforums.com/tutorials/5560-bsod-minidump-configure-create-windows-10-a.html Windows 10 Forums

[MBell11]

Thanks sahafiec, I just enabled dump files in windows. I will have to wait for the next lock up though.

As for my DDR3L motherboard, I only used it for one week, maybe I got lucky and would have hard locks later anyway... We'll never know. But the hard locks did start right away with the DDR4 board though... It would have been interesting to have more feedback from people using DDR3L boards but with Skylake almost everyone has DDR4.

I noticed some people resolved their issue by replacing the CPU, but were there many people who solved the problem by replacing only the motherboard ?

Oh and don't forget some people on tomshardware got their problem totally fixed with a new bios from gigabyte... The guy who wrote to gigabyte support linked them the tomshardware mega thread.

I think it's worth trying with Asus, I'll do it tomorrow.

[MBell11]

Done, I sent an email to Asus U.K. and Asus France, I will let you know what their replies are.

[satas]

Thanks, that's great. I can't even imagine that they could have missed all the user complaints on the net.

[CSand6]

Has anyone seen issues with the ASUS G752VT?? All drivers are up to date but the system freezes about 1-3 minutes after boot.

[CCris2]

Hi,

If you didn't update bios I advise you to update bios also, and if you still have problems, e-mail to asus tech support.

[CCris2]

Hi Berdugo

I think there is a new bios 0704 from 11.03.2016.

In this thread Theysa on page 8 had freezing problem with same mainboard.

To me its to big coincidence. 2 of the same mainboard freezing problems and sahafiec has same problem with his system with other mainboard, and I see lots of people with different mainboards with almost same problem, all have in common same mainboard manufacturer.

I don't believe that is a CPU problem. My opinion is that you guys need to stress more the Asus tech team. I think they made a mistake somewhere.

[CCris2]

Ah you have last bios, I missed that

[satas]

we have even more in common Ronin, same cpu and shipset manufacturer.

I don't want to blame one or another but also user with other motherboards (but same chipset) have the same issue.

even with different rams, regarding speed and brand.

seeing it from this point of view the only common denominator are the cpu and the chipset.

am I wrong?

anyway, acoording to my error scedule I should be getting a crash within the next 1-2 days.

I'll see what happens and report here as soon I can.

still I prefer the crash instead of someone from Intel calling me on the phone again telling me it's not Intel's fault and I'm seeing all that just the wrong way.

I'm really tired guys...

[CCris2]

Then why his system worked ok with ddr3 ? and I made 2 pc's on skylake and none have problems ... And I saw people with Gigabyte mainboards made bios update and no more freeze, and on Asus they make updates and freeze continues.

What I don't see here are MSI mainboards, that's because if you go on msi forums they have same problems but they were fixed also, some users didn't even had patience to get new bios and they tweaked voltages to make systems work ...

[satas]

because there is always a certain percentage of components failing at specific configuration and circumstances.

[CCris2]

Also MSI made in bios to select what type of memory you have Crucial, Hynix and what other are there. To me it seems some bios memory wrong setting.

[CCris2]

sahafiec finally got someone from tech support answering on asus forums, and it was a short answer: " Maximus Tweak Mode 1" . Maybe this will help also people who have memory BSOD related errors and I think freeze problems also go to Extreme Tweaker/Dram Timing Control and set Maximus Tweak Mode 1.

For 4 words he waited weeks ... nice support from asus. Lets hope that this was all.

[MBell11]

Update : the Asus tech support made me perform some stability tests with OCCT, which I already had done (no errors), and then suggested I tried Linux to see if the lock ups still happened, which I haven't done yet. Since my lock ups were getting more scarce recently, I don't have time to stay on Linux for several weeks waiting for a freeze... Do you know if someone tested their system on Linux ?

Finally she told me that if the issues were still there on Linux, I should consider returning my motherboard.

As for the bios update, she told me she did not know if the next bios would address our specific issue. And she did not seem to care about the links to the tomshardware and intel communities threads I sent her.

In the meantime I also found out that my chipset driver, the one on the ASUS website for my motherboard, was in fact not up to date (it was from December 2015), I had to go the Intel website to get the latest driver (10.1.1.18 April 2016).

I think I am going to wait for the next lock up before I decide what to do.

[CCris2]

@ Berdugo

Have you tried to modify that Maximus Tweak Mode 1 ?

[satas]

It did not really help Ronin as I had the same crash today after running error free for 4 days.

so at least for me Mode 1 was not the awaited solution, unfortunately.

[CCris2]

sahafiec

So, don't tell me that Asus made a bunch of mainboards without fully test them ...

Nice quality check and tech support they have ... is like they just started to build mainboards.