[QUOTE=Prime95;418666]Too vague. Improving:

1) Use Skylake 6770(either K or non-K) with hyperthreading enabled.
2) Use Windows 64-bit (problem can also be replicated using Linux).
3) Run version 27.9 of prime95 available at [url]ftp://mersenne.org/gimps/p95v279.win64.zip[/url]. Run a torture test. Choose custom from the dialog box. Select 8 threads, 768 min and max FFT size, in-place.
4) Failure usually occurs within an hour.[/QUOTE]

And to be clear, alternately use the latest version 28.7 but you MUST add this to your local.txt:
[CODE]CpuSupportsFMA3=0[/CODE]

That forces the code to use the non-FMA version (AVX 1.0) which is where the problem lies. Using the older version 27.x does the same thing since it didn't support AVX2/FMA yet.

I also recall that there was initial confusion about whether disabling HT helps, but that was straightened out? Disabling HT absolutely makes the problem disappear?
[QUOTE]ralleh: ...Disabling Hyperthreading will make the problems with 768k disappear...[/QUOTE]
...
[QUOTE]AGM: ...The only things that seem to work is what ralleh described already, except disabling hyperthreading in my case doesnt seem to work, but I will try again, because I tested so much in the last weeks that I cant remember for sure anymore if I indeed tested it with HT off. ... [later] ... I am running it right now with HT off and it seems to indeed work. No worker stopped after 1:30 hours yet. Ill update, if it crashes after all.[/QUOTE]

[QUOTE=Prime95;418666]Too vague.[/QUOTE] [URL="https://meta.wikimedia.org/wiki/Cunningham%27s_Law"]So I see[/URL] :smile:

[QUOTE=tha;418654]Since this issue has potential problems for the security of the systems, I mailed the security guys at Intel yesterday. They have replied to me today that they intent to forward it to the chip designers, but already try to replicate the erratic behaviour on their own systems. I also included this thread on this forum in the info I mailed them. What they like to see is a list of exact steps taken to get the processor to fail and the precise specifics of hardware and software used, even though they are already aware of the processor itself being the main suspect. You can post any such information here in this thread.

This posting is to underline the posting above of George, not to signal no further action from the community to Intel is needed.[/QUOTE]

My hardware:
- 6700k
- Asrock OC Formula Z170 - Bios 1.7
- 32 GB Ram - CMK32GX4M2A2666C16 - ver 4.31 (=Samsung)
- Noctua NH-D15
- 500 GB M550 SSD
- Win 7 64 Bit

[QUOTE]
Would anyone with a Skylake chip open their system for a ssh access and send credentials via PM?
[/QUOTE]

Sure. I've never used SSH. Is TeamViewer ok?

[QUOTE=Aurum;418742]My hardware:
- 6700k
- Asrock OC Formula Z170 - Bios 1.7
- 32 GB Ram - CMK32GX4M2A2666C16 - ver 4.31 (=Samsung)
- Noctua NH-D15
- 500 GB M550 SSD
- Win 7 64 Bit
[/QUOTE]

That's useful. But, you've claimed here there were others with other hardware which exhibited similar behaviour.

Please bring them forward.[/QUOTE]

- 6700K
- ASRock Z170 OC Formula
- 16 GB RAM - Kingston HX426C13SBK2/16 (Hynix)
- Noctua NH-D15
- 500 GB Samsung 950 Pro
- Win 10 64 Bit

[QUOTE=AGM;418755]- 6700K - ASRock Z170 OC Formula - 16 GB RAM - Kingston HX426C13SBK2/16 (Hynix) - Noctua NH-D1 - 500 GB Samsung 950 Pro - Win 10 64 Bit[/QUOTE]

Damn!

Cue the sexy girl in the tight leathers causing an explosion as she crashes her motorcycle into the security compound from height!

ASRock and/or Intel -- we might have a problem....

Yes, many of us use an OCF, simply because its a very good OC board. It was one of the first things we thought might be the cause. Then people with MSI, Gigabyte and Asus boards noticed the same problem.
I think that was mentioned already. ;)

Ralle uses the same hardware:

- 6700k
- Asrock OC Formula Z170 - Bios 1.7
- 32 GB Ram - CMK32GX4M2A2666C16 - ver 4.31 (=Samsung)

He also tried:
G.Skill RipJaws V schwarz DIMM Kit 16GB, DDR4-3200, CL16-16-16-36 (F4-3200C16D-16GVK)
G.Skill RipJaws V schwarz DIMM Kit 32GB, DDR4-3200, CL16-18-18-38 (F4-3200C16D-32GVK)

+ different 6700ks and another 3000er Ram Kit.

Dear all,

I have a skylake 6700K OC@4500 MHz, with 3000 MHz DDR3.

I was expecting a failure with 768K FFT but the program ran overnight for 7 hours on 8 threads with FMA3 disabled, with custom in place 768k test without any problems nor warnings on prime95 v 28.7

My configuration :

intel 6700K @ 4.5 GhZ + enermax watercooling kit
MSI gaming M7
SSD samsung 850 EVO
2x16 Gb Corsair low profile @ 3 GHz
inno3D GTX970 superclocked
Alim enermax platinium 850w

Best regards,
Philippe

What about 27.9? Just to be sure. And it's been reported that a small fraction of Skylakes do work correctly.

I definitely recommend 27.9 ... 27.9 usually fails a lot faster. Nevertheless there are some working combinations out there.