Single core - 100% CPU - high interrupts on ACPI

[iransofaraway]

Hi folks. I bought an Prime X299-Deluxe and a Core i9-7900X - I've had them for months now but keep having a random issue. Sometimes, after rebooting, one of my cores will be maxed at 100% constantly, and checking DPC interrupts shows ACPI.SYS is the culprit. No amount of rebooting, changing drivers, etc seems to correct it - rebooting sometimes fixes it - if I shut down completely and power off the system for like five minutes, then boot back up, the problem sometimes goes away. Sometimes I have to swap around PCI-E cards. It's just bonkers. I've built many computers in my life, and know what I'm doing, but this has me stumped.

I found this other user on Reddit having the same problem: https://www.reddit.com/r/Windows10/comments/7puiip/win_10_bug_acpisys_always_maxes_out_one_of_my_cpu... - and I have that same motherboard and SSD, but slightly different CPU. The Microsoft tech in that thread seemed to indicate that they looked at the logs and it's possibly an issue with ASUS?

Has anyone experienced anything like this on their X299 hardware? Any tips/ways to get it fixed? I'm already running latest BIOS firmware for my board, and latest drivers on everything.

[Silent_Scone]

guitardom wrote:
I reported this on this forum and others last Nov/Dec. I had a lot more participation and such on other forums, but here is the link from this forum.
https://rog.asus.com/forum/showthread.php?97880-Core-spiking-on-x299-Prime-A-bios-(0802)&p=689856#po...

Went through a bunch of back and forth with Asus. It was never resolved. I tested different CPU's and a few different motherboards.
You have 2 options, roll back to bios 0503 or move to another MB brand.

Not likely the same issue (and if it is, nobody involved in the forum discussions could debug it properly) as two of us have already established quite easily that one cause of the issue is remedied by not using certain monitoring tools. Best not to jump in a thread and suggest replacing a motherboard when you have no idea what the root cause of the issue is, that doesn't help anyone.

DooRules wrote:
I uninstalled HWMon and installed aida, one core full bore. Killed aida and the one core back to normal. Only using HWMon now, it has no issues.

I've since had a chance to test this just now. Disabling the Motherboard monitoring tools or specifically LM78, the load subsides when AIDA is running. Once AIDA are able to replicate it, we might have a better idea.

[Ulos_fr]

I make an other ticket to asus, somebody got an answer from them for these issues? One for monitoring software issue (personnaly i never have it) and the TBT 3 issue who make our core 2 crazy and create a lot of issue under OS and game?
@Raja maybe can answer us here if he can replicate?

[cRiTza]

guitardom wrote:
I reported this on this forum and others last Nov/Dec. I had a lot more participation and such on other forums, but here is the link from this forum.
https://rog.asus.com/forum/showthread.php?97880-Core-spiking-on-x299-Prime-A-bios-(0802)&p=689856#po...

Went through a bunch of back and forth with Asus. It was never resolved. I tested different CPU's and a few different motherboards.
You have 2 options, roll back to bios 0503 or move to another MB brand.

are you guitardom from DUC?

[Ulos_fr]

So what the x299 r6e is not compatible with thunderbolt 3 without issue... that will be the end of the story...
Who here can use tbt 3 on one of the asus x299 motherboard without the core 2 100% usage and can overclock without in game lag. Want to know...
*Want an official answer, or without i will sending back to amazon or asus to get a refund for lier publicity... make a turn on x299 gigabyte forum, they already fix all...

[Silent_Scone]

Ulos.fr wrote:
So what the x299 r6e is not compatible with thunderbolt 3 without issue... that will be the end of the story...
Who here can use tbt 3 on one of the asus x299 motherboard without the core 2 100% usage and can overclock without in game lag. Want to know...
*Want an official answer, or without i will sending back to amazon or asus to get a refund for lier publicity... make a turn on x299 gigabyte forum, they already fix all...

I'm having problems with this process and don't use TB3, so it's not one and the same.

[Ulos_fr]

For me right now, everything work fine without tbt3 and with this config 1080 sli pcie 1 and 3, intel 900p on pcie 4x pch, 3 960 pro (one m.2 pch, 2x on dimm throught cpu) and a hyper x16 (pcie 2) with 2 intel 32gb optane in raid 0.
All Samsung are up to date, intel also and tbt 3 up to date also.
My core 2 usage and other bug appear only with tbt3 activated (pcie 4 try with just a gtx and all other pcie port same issue)
Windows pro 1709 *up to date and all driver up also.
Intel turbo max install just disable under pop up app and computer overclock at 4.7ghz 1.18v mesh 3200 1.035 gskill 3600 16.16.16.36.2

If this information can help you, i use hwmon, aida64 and occt in last version without issue when tbt3 disable

[Silent_Scone]

I've spoken with Fiery from AIDA regarding the latency issue in tandem with using their utilities, and he acknowledges that something is making the embedded controller readout slow down on certain ASUS boards intermitantly. I'll update the thread if I hear anything else. It's very possible the issue with Thunderbolt 3 is connected on the OS side of things.

[Ulos_fr]

I open an other ticket with asus france but in complaint status, have to wait now...
But maybe we can also open a new thread with just title "Issue with tunderbolt 3 and thunderboltex III, just put a +1" and see how many +1 we will have and maybe one day we will have an official answer if we reach a big number of +1. Also make sure these thread never die and stay on top of the x299 thread list.

[RecklessNL]

Ulos.fr wrote:
I open an other ticket with asus france but in complaint status, have to wait now...
But maybe we can also open a new thread with just title "Issue with tunderbolt 3 and thunderboltex III, just put a +1" and see how many +1 we will have and maybe one day we will have an official answer if we reach a big number of +1. Also make sure these thread never die and stay on top of the x299 thread list.

This sounds like a good idea, but did we confirm 100% that this bug doesn't happen when Thunderbolt 3 is disabled / the card is removed?

Also I have never heard of Aida64, some people here keep bringing it up as if it's related to the bug - it's not. Most people here and on reddit who have this issue do not and have never had that program installed. I certainly haven't, and I've had this bug for months. Aida has nothing to do with it and is largely irrelevant to this issue.

The main point to figure out is if TB3 is the main root cause of this, or if this still happens with people not using TB3. So far, it seems most affected users here and on Reddit use TB3 card, but we need to confirm it 100%.

[Ulos_fr]

For the tbt 3 I'm sure there is an issue. Maybe there are more issues with others things who create the same result acpi interrupt and core 2 at 100%.
Look my previous post, i tried everything and changed everypart of my config to test it. I dismount my cooling loop maybe ten times ... Buying thunderboltex 3 in doble, and gigabyte alpine ridge.
I can control the issue.
Activating tbt3 --> issue ,
Disabling tbt 3 and unplug power cable (if not do issue stay) --> issue dissapear PC run smooth stable like a rock.


"The main point to figure out is if TB3 is the main root cause of this, or if this still happens with people not using TB3. So far, it seems most affected users here and on Reddit use TB3 card, but we need to confirm it 100%. "

if one day we have an answer from asus team it will be shine to begin!
And a lot of people who have this issue use X299 deluxe who is deliver with the thunderboltex 3 but issue appear also with alpine ridge gigabyte so it's not the firmware of addin card but asus x299 motherboard firmware issue. And also no thunderbolt 3 issue report on gigabyte forum with latest bios and alpine ridge tbt 3 card. Just asus x299 board are touch by this issue