6850K @4.5GHz Random Crashes

[3cl1ps3]

6850K @4.5GHz
VCore 1.338 (adaptive, all cores synced)
Cache @35, cache voltage 1.10
CPU Input voltage, 1.80
VCCSA, 1.10 maximum (via offset)
Load Line Calibration: level 7
RAM, 32GB - 2x16GB, Corsair manual mode 3200MHz
MoBo: Asus Rampage V Edition 10
Graphics card: 1080Ti
PSU: Corsair 1200i
CPU Cooling: Scythe Mugen 5 PCGH edition (air) modded, quite a lot of case fans, almost all of them controlled by the motherboard. All phases of the CPU are connected and the CPU in BIOS is set not to be power limited.

The PC would randomly crash when gaming or under other heavier load, especially when room temperature gets higher than 26-27 degrees. Even at these times the CPU package temperature would rarely reach 78-80 degrees, most of the time it would stay up to 75, core temperatures would be a few degrees lower and most of the time in their 60s. If the room temperature is in the 21-24 degrees range, there would rarely be crashes whatsoever and the Vcore could go down to 1.334 without any issues.

I can raise the VCore to 1.34 or more but when hot, this doesn't solve the problem. It looks like the issue is somehow related to some setting in the BIOS where the motherboard will take control upon reaching certain temperature stage (to prevent damage). Like there are a few settings which refer to the type of cooling the CPU is using (air vs liquid) and I believe my setting there is Auto. I may be wrong, however find it pretty weird that there are no problems when room temperature is just 4-5 degrees lower and I start getting "system thread exception" and "clock watchdog" crashes when it gets hotter. But CPU package and CPU core temperatures never reach 80 degrees, even if they approach it it is only in moments of random peaks. I also monitor all voltages that are all set manually and never exceed the above values.

Anyone got similar issues with Broadwell-E? What could be the culprit? RAM was extensively tested with Memtest off a flash drive, never had any errors. Not certain about the graphics card which is a factory overclocked Strix 1080TI edition, but it never goes (even the VRM) above 75 and looks stable. I believe the PSU is OK too. The motherboard is running the latest BIOS.

Thanks everyone.

 

[3cl1ps3]

And why on earth are you running only 2 sticks of ram in a quad channel board ?

The rig was pretty expensive at the time of purchase. I am also having a 1.2TB u.2 Intel drive that was like £800 only. m2 drives. Xonar Essence STX II etc. When initially I bought the RAM, Corsair RGB it was also over the top so in the end I decided to stay where I am and go for an entirely new rig when Intel goes for 10 nm, or AMD, but for now I will keep this rig as my main one.

Then and only then set the memory to 3200 , personally i would set the timings manually and set the voltage manually to 1.35v

The RAM runs at 15-16-16-34 1T from default/xmp 16-18-18-36 2T. Voltage is 1.35. No problems with it at 3200MHz, I tested it extensively but couldn't go lower than that. I tried and it's a downpour of errors.

Fully manual mode works fine at 4.5GHz but keeps the VCore constant. The VCCSA is static, I can lower it a little bit more but in adaptive VCore mode it can be done only by an offset, thus it is quite a lot of play and test to get the final result at OS level.

4.4GHz manual is unachievable on my chip below 1.299 (call it 1.30). More or less 0.4+ is the step every 100MHz over 4.2. Isn't LLC 4 too little, even if I increase the input voltage? 4.5GHz even in manual mode would not boot under LLC 7 and 4.4GHz wouldn't boot under LLC 6.

Are you all manual 24/7 on your 6950X and at what VCore/input voltage and frequency? What I want to know is why the system is fully stable at temperatures below 75 and start crashing just 5 degrees over it. I know this is a consequence, not a reason but there must be something that triggers it. I believe derba8er had a video about broadwell-E where he adjusted some BIOS settings about temperature thresholds on his 6950X and Rampage V E10. I need to watch it again.