Possible fix for Intel CPUs crashing

[zzetta]

Hi there.

I am posting this because I had a similar cpu instability issue with my new 14700kf with default bios settings. After many tweaks, tries i have found (possibly) a fix for newer intel cpus unstability at default/stock bios settings.

After reading articles about new intel cpus not being stable on stock settings i went ahead and tested my new 14700kf on my z690 aorus elite ddr4 board. Using stock settings, i started Prime95 small fft AVX2 torture test and everything was fine, for about 20 minutes, after which my pc bluescreened. I was mortified. Why would a new intel cpu bluescreen on stock settings??? This was the beginning of my journey in finding a fix.  First i tried to enable intel power limits which is not applied at stock settings. My motherboard would default at 4095w PL2 and 280w PL1. After setting the INTEL power limits, the crashes dissapeared, but i still wasn't happy with the fact that my new cpu was not stable with unlocked power limits. I mean, my old 9900k was overclocked with unlocked power limits, eating up to 250w and after 4 years it did not degrade at all. So I reenabled auto power limits and i started switching options in bios. After 2 days of turning on and off settings in bios, I have found something called "IA CEP" which was on auto. After i disabled that setting, all of the instability with Prime95, Cinebench R23,R24 simply dissapeared. Not only that, but now I can run with auto power limits(4095w/280w) and I don't have any crashes no matter how hard the cpu test is. Also the load voltage seems to be more stable on loads, cpu temperatures are a minimum of 5c lower in most of the tests/games, and i have more fps and more consistent frametimes on games like cs2.

So what I can say is that this IA CEP setting needs to be addressed. In my case it was not the higher power limits as many people stated, or bad motherboard loadlines, it was this Current Excursion Protection that affected the stability. Reading online, this setting is implemented by Intel in the cpus, not motherboard vendors, thats why I am posting here, maybe it will help somehow.

Have a nice day.

[zzetta]

The CPU is fully stable and can handle any amounts of current and watts i throw at it:

Notice the green and orange lines. It spiked to 300 amps and almost 400w and it did not sweat at all.

With the previous BIOS (F29) such a spike would cause an instant BSOD.

F26 fixed everything.

Also,

It seems that my posts that did not work when I wanted to post them got posted now. Buggy forum.

[zzetta]

I'm coming back with another extreme test, Linpack Extreme with 20 consecutive passes with a huge dataset of 30 Gigabytes.

[zzetta]

And now again with Linpack Xtreme but with updated Intel Math Libraries from 2024. This one hits even harder, but it's stable. The cores spiked to 107c and had no issues pulling through.

[Yuvaletzi]

I’m happy to see that you sorted things out and you got stable !! Nice research over there, I. Really hope that Intel could do the same , I just finished my build with apex encore and 14900KS + 8400mhz g skill ram fully passed memtest86 6:10 hours now I wanted to consult about some bios settings should I leave IA and SA CEP on or off? My LLC is level 3 and svid behavior trained is that ok ?

[zzetta]

Yea, you just have to correct AC Loadline yourself if the cpu is unstable. BTW, it didn't have anything to do with IA CEP or other settings.

You can use my guide: https://community.intel.com/t5/Processors/Guide-Addressing-CPU-Instability-on-Gigabyte-Motherboards/td-p/1596899, but that is for Gigabyte MB's. You can google on how to correct it on Asus Motherboards. My last asus mb had ac loadline settings and i only had to set the AC, and leave DC on auto for correct readings. Another thing, asus starts from 0.01, and i think that would be equal to gigabyte's 10.

[zzetta]

my bad, 0.01 on Asus would be equal to 1 in Gigabyte. But if your AC loadline is 0.55 on auto and the cpu is not stable, you raise it to 0.56 and so on. You dont have to change anything else, like LLC or power limits. You can actually unlock the power limits and then set the AC

[Yuvaletzi]

So if I understood correct AC/DC need to need the same values and I need to find the correct value myself?? CEP off can degrades my cpu? And why not changing LLC instead of messing with the ac/dc ?

[zzetta]

1. They don't have to be the same value. Leave DC on auto and if you are unstable on certain workloads just raise AC loadline until it's stable. 

2. IA CEP should be left on auto. 

3. BTW these AC loadline settings should be touched only if you are unstable and without any intel/baseline profiles enabled.

4. LLC should be left on auto because the auto setting has the most VDROOP and it is the safest way of operating for long term usage. Raising LLC will add overshoot and it can potentially degrade the chip in the long run, but from my experience on my old z390 a steady loadline didn't affect my 9900k at all.

5. Changing the AC loadline will only move the requested voltage up a bit and in very small increments, meaning that this is the safest way, and the most efficient in terms of power usage and heat the cpu generates.

[Yuvaletzi]

Thanks for the detailed explanation someone said me that CEP ON can prevent voltage spikes so it’s good for not to degrade the chip is that true? The auto settings for me is disabled I think

[zzetta]

IA CEP should be left on auto. That setting will cripple the performance of the cpu it it senses that it does not receive enough voltage for a given workload. It does not prevent overshoot/ spikes in voltage. Raising LLC will give you spikes. That's why tuning AC LL is the safest way. 

[Yuvaletzi]

Ok so right now I’ll keep the settings as they are if I’ll encounter any instability I’ll keep you posted , I didn’t found a time yet to test my system , by the way I know it’s not related but my system is new and I don’t want to install bloatware I won’t need this is a gaming pc which I only use to game on steam likely can I count on windows 11 security ? Or should I install antivirus anyway?
Btw during installation of windows 11 the WiFi couldn’t find any network it’s because the drivers I assume but it won’t come with windows installation for apex encore ?
Sorry it’s not related but you look like who I can trust

[zzetta]

You should be fine without an anti-virus. Windows does a pretty well job on its own. If you have issues with drivers, install them from your motherboard support page.

[zzetta]

I want to add here the definitive solution for the instability issue for the people that visit this thread:

https://community.intel.com/t5/Processors/Solution-for-Intel-CPU-Stability-Issues-Lower-Temps-amp-Better/m-p/1608867#M73676

[JKelso1983]

So can this be done with the latest bios update or would I have to downgrade the bios with your settings? I am having so many problems with my PC freezing and could use some help in a step by step manner if possible?

[zzetta]

If your current bios has the Intel default profile and you have no idea how to disable it, then you have to install a previous bios that doesn't have it. If so, flash an earlier bios, reset to defaults, then apply the settings I posted in my thread here:
https://community.intel.com/t5/Processors/Solution-for-Intel-CPU-Stability-Issues-Lower-Temps-amp-Better/m-p/1608867#M73676

[KrissyG]

that is by far one of the worst advices ever.

Flashing BIOS to an older version, means to download it manually.....and if you download BIOS for a different motherboard, and then you flash it, you may not be able to undo it. 

Changing BIOS settings is the better option.

[zzetta]

If you buy an unlocked CPU from intel, I think, you should be at least able to find the correct bios for your motherboard and flash it.
A K CPU has some meaning in buying it if, in my opinion, people want to play with it, like overclock, tweak voltages, understand what a loadline is, knowing how to correctly read a voltage, etc.

All the findings posted in my threads are the result of having this prior knowledge which helped me fix the instability and now I share these findings. It is still your choice if you want to try these things. I just posted here, in hopes that other people will find these helpful, therefore they will not have to RMA the chips, saving them and intel time and money.

[KrissyG]

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@zzetta wrote:
If you buy an unlocked CPU from intel, I think, you should be at least able to find the correct bios for your motherboard and flash it.
A K CPU has some meaning in buying it if, in my opinion, people want to play with it, like overclock, tweak voltages, understand what a loadline is, knowing how to correctly read a voltage, etc.

All the findings posted in my threads are the result of having this prior knowledge which helped me fix the instability and now I share these findings. It is still your choice if you want to try these things. I just posted here, in hopes that other people will find these helpful, therefore they will not have to RMA the chips, saving them and intel time and money.

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you previously said "If your current bios has the Intel default profile and you have no idea how to disable it, then you have to install a previous bios"

You literally suggested someone who may have NO IDEA how to disable a profile in BIOS, to flash BIOS.
Think of it, if you have no idea how to change BIOS profile, do you automatically know how to flash BIOS?

Also 'K' , 'KS' or 'X' series of CPUs may have higher stock frequency, more cache or better AVX or SSE version, you do not necessarily buy such CPUs to overclock them.....bcoz overclocking gives you at bets few % more performance while taking twice the power = OC is useless, it's a toy.