I just killed 2 i7-8700k in a month

[SmOKeY89]

Hello guyz. I experienced a very unusual situation with my last build.
It's my second custom build. My first was back in 2011 with the legendary i5-2500k which is still running flawlessly.
(Still overclocked to 4.2, with offset voltage.)
However I thought that it's time for an upgrade after all these years.
So I started to look up after parts, and after a lot of study, I decided to pick up the following components:

Motherboard: Asus Maximus X Hero (no wi-fi)
CPU: Intel i7-8700k
Cooler: Noctua NH-D15
RAM: GSkill TridentZ RGB 16GB DDR4 3200MHz, CL14 (2x8GB, dual channel)
HDD: Seagate FireCuda SSHD 2TB SATA3 7200rpm
PSU: Seasonic Focus+, 750W, 80+ Platinum
Case: Sharkoon DG7000-G

Components moved from my old PC:

HDD: Seagate 2TB ST2000DM001, SATA3
SSD: Kingston HyperX Savage 480GB, SATA3
VGA Card: ASUS GTX760-DC2OC-2GD5, 256bit, 2GB (I haven't upgraded 'cuz of these insanely high prices nowadays, damn you miners)

So, I happily assembled my new system, it worked after pressing Start button for the first time. (usually this is rare hehe)
At start I thought not to owerclock, just let's see how it works.
I kept using it for about a week, measuring temps, then I started to mess around in bios to try overclocking the system.
(also updated to the latest v1003 Bios)
My main reason was not the +200,300Mhz gain, but the thing that I noticed some high voltages with stock mobo owerclock.
(sometimes hitting past 1.4 volts, at 4.7Ghz).
So, like I did with my last build, I tried to use offset owerclock, because I like to keep it on low voltages while
my system is not on heavy loads. (tried adaptive first but I didn't really got the desired voltages, 'cuz while heavy load,
the system always worked past the voltages that I have set in bios). I found my system stable at 4.8Ghz at around 1.28v,
with likeable temperatures around 80C while running Prime95 no AVX, and AVX hitting 85-86C. (this was manual, all time at same voltage setup).
Then I tried adaptive voltages, didn't liked it. Moved on to offset. Now I know that I messed it up by giving too much + offset,
ending up killing my CPU. (Mobo was showing Q-Code 00 all the time, and below where the Leds are, my CPU led was red).
No problem, I have warranty, so I sent it back for replace.
Got my new i7 after a week, so I started to mess around again in bios, to set a stable owerclock.
Again I found a sweet spot around 1.26-1.28v, but now for 4.9Ghz. I've set a -30 offset. It worked great while testing.
I forgot to mention that in the first case I had XMP profile set up for my RAM, to be able to run it at supposed speed, 3200Mhz.
With the replaced CPU I left alone XMP and just entered manually the settings (DDR4-3200MHz, 14-14-34, 1.35v, even lowered the
VCCIO voltage to 1v and the System Agent voltage to 1.1v, because i thought that auto is giving too much.)
So I went happily to sleep after all day messing around with owerclocking, thinking that finally my system is stable.
Then in the morning when I woke up, I started my PC. It started with double boot and it restarted like 3 times, no post,
ending up killing my CPU again. (from what I think). Now I've got "0d" in my Q-Code display, and the same red CPU Led under.
So I've sent it back again, and I'm waiting for the new one again.

I've decided to write this because I am left without any more ideas.
Killing 2 CPUs in a month is kind of rare I think.
I haven't bought this i7 to not be able to owerclock it, especially when stock voltages are insanely high,
and I know that by manually settings i can go a lot lower, at even higher core speeds.
What am I doing wrong? 1.28v isn't supposed to kill my CPU.
Again with my second owerclock i haven't passed 85C in tests.
What I am thinking of it's maybe my RAM is killing it? Maybe I have to stay bethween the safe maximum speed (it's 2666Mhz for this i7).
I really don't know what to do anymore. I am open to anny suggestion.
Thanks for reading this "book" I wrote. And have a nice day.
(sorry if I'm ain't writing gramatically correct, I am not an english speaking person)

 

[Johan45]

I would suspect the motherboard, possibly a bad BIOS. Killing two CPUs is rare but I have seen boards that do that and also bad BIOS that kill CPUs. At minimum I would change BIOS before your new CPU arrives.
In instance number 1 unless you set an outrageous voltage for the CPU I doubt it was your doing seeing the pattern here

 

[SmOKeY89]

Hello. Thanks for the reply.
My bios is the latest bios available for this board. (v.1003)
I even tried the Bios Flashback with USB stick. (same version)
Which worked, hopefully by this I can know that the Mobo is working, and the CPU is the one that is not.
(all coolers work, led lights work, etc.)
BUT maybe my motherboard doesn't allow that kind of owerclock? Maybe it's a faulty one?
I'm really left without ideas. Since I paid a lot of money by building this rig, i have a minimum expectation of owerclocking.
And in my opinion 1.28 isn't overvolt.

- - - Updated - - -

Especially since automatic owerclock puts more voltage than I do. I even saw passing 1.5v. So I really don't know what can be the issue.

 

[Johan45]

I don't think it was anything you did. I would also flash bck to a previous BIOS not the same one

 

[SmOKeY89]

Also a really odd thing. From what I heard it's better to disable MCE, while owerclocking. (Asus Multicore Enhacement)
But when I do that I observe that voltages increase a lot. While MCE enabled I never saw voltages
pass 1.31 at 4.9Ghz in my case. (while testing offset with auto -.minus). And when I disabled it it went
past 1.4v, sometimes even hitting 1.5, also when idling after a simple boot.
So it is possible that I have a bad board? And by "bad" I mean it's simply doesn't letting me very much room for overclock.
It is very possible that I'll get my 3rd CPU shipped back, owerclocking again, and experiencing the same issues as before?
Again and again this **** is letting me think about my RAM speed and XMP profile.
Thanks for reply.

 

[Johan45]

You seemed to be doing fine until you updated the BIOS and overclocked. So it could be the BIOS file, could be the motherboard. Like I said put the older BIOS back on. It's not the ram or XMP that's doing it.

 

[Nebulous]

As Johan suggested; flash to older bios. But I would suspect the board. Instead of swapping CPU's again, I would swap the board. You mentioned you swapped 2 cpu's in the same board and getting the same result ie: dead cpu.

 

[SmOKeY89]

The thing is I cannot find bios v0505, which was my bios the board shipped with, only v0802.
I will backflash it for test. By the way i just observed that a new bios came out for this mobo just now, v1101.
I'll wait for the CPU to come, after that i'll flash the mobo with this new bios version.
Sadly it doesn't give any description about improvements, so it will be a "shoot in the dark".

 

[Johan45]

Smokey that avatar has to go. This is a PG forum no swearing.

 

[Dr. McCoy]

I too believe it's a buggy BIOS - I've seen where issues like it were reported along the same lines, overvolting stuff by default.
My IX Hero volts up to 1.35v's as a default voltage, good thing here is I have a rather large cooler on it so it can handle the heat while getting things right.

Noted you are using "Offset" to determine voltage, that's something I never use for anything except for extreme tweaking. I always use the manual mode setting so what I set it for it is or very close, get the math wrong using offset and you may overvolt it without even knowing it. All it takes is that one time to get it wrong and it's game over for the chip.

If possible I'd suggest along with the 8700K to pick up a cheap Pentium/Celeron chip for testing, this way if that's the cause you've killed a cheap chip, not the one you're really wanting to run.

EDIT:
Using anything but manual could be taking a chance since if the BIOS is buggy, it may well not be managing voltage properly.
At least with a manual settting you're directly determining what's it's supposed to be, increasing the chance it will be OK.

 

[SmOKeY89]

After some more study, I found out that some guyz were suggesting changing IA AC/IA DC Load Line values both to 0.01. These actually helped several people
to lower their voltages while using adaptive owerclock. Dr. McCoy, I understand your opinion about staying with manual, but I like to keep my voltages as low
as possible, temps also, while system is not at full speed. That's why I used offset for example in my last build.
I will definitely try this tweak when my CPU comes, and I'll flash the new bios version also, maybe they've optimized this board better with this new bios version.
I will post my results. Thanks for the reply guyz. If some of you have some more suggestion with bios settings, or if some of you can post their exact bios settings using this board and this chip, I am open to discuss. Thanks

 

[SmOKeY89]

Finally I received my replaced i7-8700k after almost a freakin' month. Since my last post a new bios became available (v.1301). I flashed it using USB Flashback when my i7 was sent for replacement.
So I don't know what to say. Now I managed a simple 4.8 Ghz overclock using either adaptive, either offset mode at around 1.26v.
Maybe I just was really unlucky with the previous processors, maybe the bios was buggy and so on....I cannot guess.
One thing is sure. Those IA AC/IA DC settings need adjustment. (putting the value 0.01 at each brings the vcore close to the vid value).
I'm still experimenting, but in main I think everything is okey now. If somebody wants the exact settings just to make an idea, i will post it if you ask.
By the way thanks for all for the replies. Keep it up!

 

[wingman99]

Glad it is working well for you.

 

[Alaric]

Finally I received my replaced i7-8700k after almost a freakin' month. Since my last post a new bios became available (v.1301). I flashed it using USB Flashback when my i7 was sent for replacement.
So I don't know what to say. Now I managed a simple 4.8 Ghz overclock using either adaptive, either offset mode at around 1.26v.
Maybe I just was really unlucky with the previous processors, maybe the bios was buggy and so on....I cannot guess.
One thing is sure. Those IA AC/IA DC settings need adjustment. (putting the value 0.01 at each brings the vcore close to the vid value).
I'm still experimenting, but in main I think everything is okey now. If somebody wants the exact settings just to make an idea, i will post it if you ask.
By the way thanks for all for the replies. Keep it up!

Settings are good. While every mobo/chip has its own personality, a successful OC's settings can give someone a "feel" for what they should be looking for, especially if they're just getting started and doing a search on the subject.