8086K issues

[andyartois]

Thanks to the usual excellent service from Overclockers today an 8086K dropped through the post box today. Unfortunately it's proved not to be a smooth ride, I seem to be getting odd boot issues, sometimes failing to POST with different codes, when in the UEFI it can be sluggish/unresponsive and even a distorted screen. Other times it can take several minutes to finish the POST before getting into Windows 10. Applying the XMT profile causes instability in Windows whilst running at stock (MCE on or off).

I cleared the CMOS after removing my 8700K and set back to the usual settings but alas the problems persist. Am I early to the party here, do you think a BIOS update is needed? I had no stability issues with the 8700K so it does smack of a compatibility issue. Not trying for any overclocking at this stage, just looking for a stable system. Not much online about the 8086K yet so any help welcome. Temps look fine, CPU shows up correctly in both the UEFI and CPU Z.

Specs:

8086K under Corsair H115i AIO
ROG Maximus X Hero Z370 with latest 1301 BIOS
16GB Corsair 3000 MHz (2 x 8GB)
850W Corsair HX850i
Samsung SM951 M.2 PCI-e ACHI SSD 512GB
AMD Radeon 470 4GB
4TB Seagate SATA drive
Sound Blaster Z

 

[andyartois]

Possibly due to overtightening the cooler?

Excellent shout, I had tightened the AIO with a screwdriver (had stopped when I felt resistance), I loosened slightly so these were hand tight. Seems to be booting each time now which is great progress. Thanks for the pointer.

I still have an issue setting the XMP profile however. Whilst it does apply the correct timings on the RAM I have noticed the core voltage shoots up from 1.120v to 1.41v when this is applied. The clock speed also drops back from a 4.3GHz all turbo stock speed to 3.2Gz under load which suggests it is throttling with that voltage. The UEFI becomes sluggish with the XMP setting on and I get oddness in Windows with display issues such as "link failure detected" which kills the refresh rate on my 4K monitor from 60Hz to 30Hz and general instability so have reverted back.

BIOS shows no changes to the voltage settings as Auto is left selected when applying XMP so no idea where this cure voltage oddity is occurring. Again I didn't have this issue with the 8700K, just the memory timings used to change when applying XMP. I have reverted back to non XMP settings for now and will hold out for a BIOS update, suppose I could try to dial them in manually.

OP easy solution. Pop the 8700 back in.

Well where is the fun in that Seriously though it might be worth a test to see everything works as expected. Have a buyer waiting for the 8700k so will put them off for a few weeks.

What's the cashe /uncore speed on these things ?

Same as the 8700K, this just has a higher single core boost and default clock speed. Exactly a 0% increase in performance on a fully threaded workload to keep inside the same TDP.

 

[andyartois]

Did you manage to find out what the issue was, as i also have the ROG Maximus X Hero Z370 with latest 1301 BIOS and was planning on getting the 8086K to replace my delidded 8700K, but now a bit dubious about buying one..

I have managed to dial in the XMP settings manually and the core voltage is behaving so it just looks like the XMP loading in the BIOS is bugged with the 8086K or at least with my memory. Still occasionally fails to POST after a reboot (cold starts fine) but fully stable in Windows now. What sort of speed are you running with your delidded 8700K? I haven't played much with the overclocking yet but getting a stable 4.8GHz all core turbo with 1.184 V after a 36 hour stress test so there looks to be headroom on the clocks. 4.9Ghz pushes the thermals out of spec in this weather at full load without the delid so if anything getting slightly worse temps than the 8700K, could well be my AIO mounting however. As an FYI I run at 100% load 24/7 on BOINC so it's an unrealistic stress than most people will put on this.

I see Overclockers are selling our MB with this CPU so I assume they had success with the 16GB Team Group "8Pack Edition" Xtream DDR4 4000MHz Memory they are shipping it with. Still holding out on a BIOS update...