Smart Security 5: What would cause ekrn.exe to use 10% CPU usage every 5 seconds?

ESET Smart Security 5 has been running great except for one very noticeable issue...

In task manager ekrn.exe is using 10% CPU Usage every 5 seconds and I don't understand why?

 

ekrn only does something when it's given something to do. Is there software running that opens/creates/modifies something every 10 seconds?

 

I noticed this when the system was idle and nothing else was using CPU, only ekrn.exe.

 

Perhaps it was in the process of updating / startup scanning?

 

I just checked ESS, nothing is scanning or updating, and the ekrn.exe just spikes to 8% CPU every 5 seconds for no reason?

 

Well it is better than what mine has been doing. I see a nice short sine curve out of the CPU usage after it has been idle for a short while. My CPU usage is actually LOWER when it the computer is in mild use than when it is "idle". When idle it will spike up to 50% and then down to zero and back up. I've had it working great for a short period of time for some reason it seems to break itself somehow..

System specs:
Win 7 x64 SP1
Radeon HD5770 with Cat 11.9

 

Maybe the System restore feature is backing up files in your system, and that can be the reason for the scanning during inactivity.

 

If disabling real-time protection makes a difference, I'd suggest creating a Process monitor log and supplying it to customer care to find out what files were actually scanned.

 

Nada to both, I have disabled both the real time protection and the firewall to see nothing change as far as CPU usage goes, and as far as System Restore goes I have that completely off. Not to mention it makes no sense for a minor scan like that to take up that much CPU usage my Phenom II X4 925.

EDIT: I think I have found the culprit so far as long as it doesn't start up again. I installed ESS5 on a clean install while monitoring CPU usage and it idled fine. After that I installed PD12 and set it up CPU usage spiked. I turned off Auto Optimization and CPU usage went back to normal.. I'm not sure why this would cause a consistent cpu usage spikes (up to 50% of 4 cores) in ekrn.exe but it was.