CPU with only one core at 100%

[wobbleidz]

So I have the following issue.
My CPU0 occasionally spikes to 100% and stays there, out of nowhere. Rest of the cores are fine and don't spike, but just that one core is at maximum, in idle! There are no high temps or anything like that. Whenever the CPU0 (thread1) is at 100%, the computer stutters, lags like hell and I can't really do much, which is weird because the overall cpu usage is at 20%-30%... I have no idea what's causing this, hence why I'm posting here, maybe someone else experienced this?

MY config:
i7 4790k (not OC).
GTX 970
12GB RAM
1 Intel SSD 180GB
1 Kingston SSD 120GB
1 Seagate HDD 1TB
1 Seagate SSHD 2TB
Motherboard:  ASUS Z97-PRO GAMER 
I run a dual monitor config.

---

If someone else experienced this and knows how to fix, that'd be great.

 

[rgd1101]

open the task manager and see what doing the 100%

 

[wobbleidz]

I did that already, nothing is out of the ordinary.

 

[rgd1101]

not when it working fine, when that 1 core using 100%.

 

[wobbleidz]

Yes, when its using 100% I checked.

 

[rgd1101]

so no process running when it hit 100%?
because "nothing out of the ordinary" doesn't help at all.

 

[wobbleidz]

none is at 100% or even at 20%. I already thought of monitoring it and see which process does this so I can shut it off, unfortunately tmgr and resource monitor don't really show anything that I can grab onto, It must be a single threaded malware of sort (I hope), because only one of the 8 threads is at 100%. This morning everything was back to normal but it's annoying when it pops in out of nowhere and starts stuttering my PC and lags it. Can't pin point it...

 

[gamerk316]

Make sure to enable "Show processes from all users", might be a kernel task or something.

 

[rgd1101]

if you think is a malware, did you ran any malware scan?

 

[wobbleidz]

if you think is a malware, did you ran any malware scan?

I did run one with Malwarebytes, found a few small things and removed them, but I doubt that was it.

 

[wobbleidz]

In an update to this thing, I noticed that a process named System Interrupts is using more than usual and maybe thats the issue, anyone know what this is?

 

[wobbleidz]

Update: Does the same thing on clean install of Windows 8.1