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.

[CCris2]

Do you have this problem in all browsers, or only in Internet Explorer ?

[ssote]

Ronin wrote:

Do you have this problem in all browsers, or only in Internet Explorer ?

Have a problem in all browsers Chrome, IE11, Edge, with opining a lot of tabs past 50+ Chrome holds out the best before problems like it tries to reload the crashing pages.

[CCris2]

Well, you need to test it with Prime95 also. When I open 50 youtube videos in browser, I don't have crashing pages it's just that the CPU gets very loaded ans starts moving a bit slow

[ssote]

Ronin wrote:

Well, you need to test it with Prime95 also. When I open 50 youtube videos in browser, I don't have crashing pages it's just that the CPU gets very loaded ans starts moving a bit slow

Prime95 never fails in the two weeks of testing, I just have got IE 11 stopped working.

[CCris2]

How is CPU Vcore voltage set ? Auto or Normal ? because there is a problem there you have a minimum voltage of 0.012V ...

[ssote]

Thanks for pointing that out I will work on it, I still have all my C states enabled. What is your Vcore minimum how do you have your settings?

[CCris2]

My mainboard is Asrock z170 Extreme 7+ . All voltages are on auto and enabled XMP .

[abarb]

But you work to Intel. Many users have skylake bug question, when Intel would fix the cpu's?

[CCris2]

I don't work at Intel ... In my opinion is more like mainboards bugs. Some people from forum, I know; sahafiec: changed 3 CPUs and 4 memory kits and in the end he changed voltages on mainboard (on an asus mainboard), and lks70 was having big problems with an asus mainboard also (even with changed voltages was not working), and changed mainboard to an asrock, enabled XMP for memory and no problem at all.

Also there are some more people that changed voltages on different mainboards and the problems were fixed.

There are some people who had problems no matter what settings they were doing, because incompatible RAM modules.

I don't say that maybe there are no problems with some CPU's, but I believe that some CPU manufacturers, either have bad quality check, or they made their mainboards settings by the best CPUs they had, without taking in consideration the tolerance margins that are in the CPU specifications documents.

I don't have anything with any manufacturer I saw problems on all, bigger or smaller, and not only with CPU.

What is the problem you have andre_luiz ? What is the system you have (specify all configuration by model numbers).

[abarb]

I see you in all intel problems (many types of cpu's and systems) of Intel fórum... How many computers have you?

[ssote]

Ronin wrote:

My mainboard is Asrock z170 Extreme 7+ . All voltages are on auto and enabled XMP .

Thanks for the voltage speciation's of your board after exactly 30 days trying to figure out why my PC is unstable I have found the memory wont run XMP stable enough for windows, it passes all memory tests however when ever I set it to XMP it corrupts windows and IE11 in memory so I have to reboot all the time. So I did the RMA for the memory.

I found another problem when using sleep mode for long period of time when waking from sleep mode with no load the CPU usage is 30%. When Booting up from shutdown it is 0% CPU usage. I have two screen shots one with Boot up one with Sleep mode.

Now that I found both problems my PC is stable however I don't know how to fix the sleep mode problem?

[CCris2]

Hi wingman99,

You bought new memory, or they changed it ?

I think you should wait till anniversary release of windows 10 about 1,5 weeks.

They changed lot of things in the new release, and if you start debugging will be pointless, because maybe the new release will work ok.

[ssote]

I

Ronin wrote:

Hi wingman99,

You bought new memory, or they changed it ?

I think you should wait till anniversary release of windows 10 about 1,5 weeks.

They changed lot of things in the new release, and if you start debugging will be pointless, because maybe the new release will work ok.

I purchased temporary G.SKILL 2400MHz Memory from newegg while waiting for my RMA on my G.SKILL 3200MHz Memory and now my Gigabyte Z170 HD3 is running perfect on both setts of Memory with X.M.P on and off, as before I could not tell what the intermittent problem was coming from. One thing I noticed with the both of new memory that I used there is no consecutive beeping sometimes when changing CPU or Memory settings, I thought there was something wrong with the motherboard now I know it was the Memory.

[DGlan3]

I just had it lock up with c-states and EIST disabled running 6600K at 3.6 GHZ 1.16 volts... sigh I should have kept my sandy bridge build... doing this whole troubleshooting process to see if it's the mainboard, CPU, or memory is a pain.

First freeze since I disabled these items and has not frozen within 10 minutes of playing diep.io like it usually did. Still back to square one now.

[CCris2]

Hi dissident ,

What is your configuration ?

Please give details with model numbers, and put CPU on auto voltage.

[ssote]

dissident wrote:

I just had it lock up with c-states and EIST disabled running 6600K at 3.6 GHZ 1.16 volts... sigh I should have kept my sandy bridge build... doing this whole troubleshooting process to see if it's the mainboard, CPU, or memory is a pain.

First freeze since I disabled these items and has not frozen within 10 minutes of playing diep.io like it usually did. Still back to square one now.

Try PassMark Memtest86 to test your memory, Try prime95 Blend to test your CPU and memory together. Tell me how that goes?

[EKnya]

Hello there people, its been a couple of weeks since i've built 6700k based pc.

My motherboard is gigabyte z170x gaming 5, and a set of ram is 2x8gb AMD sticks with XMP profile for 2666mhz.

It's been fine till i got this hard freeze with reset button not working , randomly after alt-tabbing from latest Hitman game and doing something in google chrome. (it was working like a charm quite a while)

After that it kept freezing with any sort of cpu load, i used prime95 1344k test for a measure - it just instalocked until i loaded optimized defaults from bios.

Right now it works, what i did is:

1) updated to latest bios, default was F3. In f5 it claims to "update cpu microcode" and "improve xmp compability".

2) turned on only one of the c-states, c8 and eist. Everything else is disabled.

3) tested with prime95 1344k. It works fairly well, 4.6ghz with 1.356v load voltage, no hard locks or errors.

4) checked my mb memory compability list - my set of sticks isnt there. Is there a slight chance this might've been the reason? Memory also passes prime and memtest.

I am sure anything else is default, memory voltage is set st 1.2 which is supposed to run at.

I hope there wont be anymore locks, but still.. Any advice on how i might reduce the chance of getting it? I'd love to leave c-state ON.

[CCris2]

Hi BillyWelling,

First of all you should check if your system is stable without overclock. If it is, then it is ok, if it's not then you should modify some voltages.

When you overclock c-states should be left on auto and if it is necessary mainboard will automatically disable if it's needed (if bios is smart enough).

[EKnya]

After this bios reflash it is stable in both stock and oc configuration, like i said - i am using prime95 1344k fft test.

Maybe i should check vccio and vccsa voltages you mentioned above to another guy? What it should be for 2666 ddr4? I'll do that when i get back home this evening.

If i leave c-states on auto, it keeps cpu idle core overvolted at 1.396, and drops it to 1.356 under load. 1.356 is a stable minimum, it crashes at 1.344.

In llc i only have auto/normal/high. I left it on auto.

[CCris2]

What are the options for CPU voltage. Does that mainboard has Adaptive voltage or something like that ?