Just updated my windows 10 today to the above build. Love how cortana uses your gpu in the background. 
 
Noticed this by opening afterburner & seeing one of my cards running at full speed for a second then going straight to idle speeds after a few more seconds. Closed afterburner & reopened it & noticed the same behavior. Closed afterburner. Downloaded process explorer and suspended SearchUI.exe, opened afterburner, problem fixed, closed afterburner & reopened it again, again problem fixed. Closed afterburner.
 
Resumed SearchUI.exe via process explorer, opened afterburner, problem is back.
 
Removed cortana completely from system. 
 
Had to fix all the event viewer errors associated with removing cortana. 
 
Event viewer is now error free on every reboot. 
 
 

DAVE2HOT4U
I was thinking of doing the same thing ! Glad to know it runs fine after removing. I havent switched yet.

Yep, runs fine without cortana. 
 
My windows 10 build was stuck on 10240 so I had to re-install completely. 

EVGATech_ErinW
I wonder if this had something to do with the SLI bug in the last couple Insider builds. There were some reports that disabling the SearchUI.exe would let the SLI settings apply without the secondary card disappearing from the control panel. I just updated to build 14342, and the bug seems to be gone. I don't use Cortana, but I might turn it on to see if this bug pops up.

I disabled cortana and it was still doing it.

EVGATech_ErinW
I'm wondering if it's something to do with leveraging GPU power for speech recognition. I recall seeing recently where there was an Intel driver update for Skylake and the "Gaussian Mixture Model", that seems to have something to do with Nuance and their speech tech using GPUs for this.

No idea. Are you seeing the issue running the latest insider build?

Ok, so I activated Cortana, and sure enough, when it loads, the GPU clocks spike to 1235, then drop back down. However, I'm not sure if this is related to the search and voice processing, or that it might use hardware acceleration for window animations and such. 

I gave up on win10. Anything pass Win7 seems to be a EPIC FAILURE!
Win10 worked well up until a little over a month ago and then Windows Explorer would randomly crash and start. Went back to Win7 after that
I went back to Win10 about a week go so I could play Quantum Break and everything was fine up until 20min ago when Windows Explorer yet again started to crash and restart, but now instead of being random it's now doing it every second
I'm not understanding how you guys can stand to use this garbage. MS has gone down hill and is making a Apple computer look good

Noticed some other odd behavior after letting my system idle for 5 minutes. 
 
Systemsettings.exe
Microsoft.Photos.exe
WinStore.Mobile.exe
 
All start to run by themselves in the background after idling for 5 minutes. 

Sajin
Used regedit to remove all permissions on those three .exe's to prevent them from loading. Success. Now they won't load after 5 minutes of idle. I can't launch them either.
 
Now instead of those three launching after 5 minutes of idling windows calculator opens after 5 minutes of idling. WTH? 
 
Now calculator permissions have been removed too. Now nothing launches after idling for 5 minutes. 

Shouldn't even have to go through all that
And WTH!! are programs starting up when the computer is idle? What sense does that make

Hmm, I had Win 8 and then updated to Win 10, almost all my games stopped working. I made restore of system to Win 8 and always great, because my PC was produced for Win 8. Probably this is your solution too.

mike406
Is completely removing Cortana a difficult process? And does it hinder normal search functions? I haven't looked into it yet but I'd definitely like it gone if it's using my GPU for no reason.

I turned Cortana off or disabled it somehow. I can't remember which but I do get a lot of Errors and Warnings about not being able to connect to or update Windows Store which I disabled too. I have enough problems. I don't need my PC listening to everything I say on top of them. It's bad enough having Siri listening to me all day long just hoping I'll say, "Hey, Siri" to wake her up. Glad I don't have the Xfinity garbage. What people don't realize is that it might be easy just talking to your remote, but the thing is always listening to everything going on in your house.

Windows update yesterday 6/14 brings Windows 10 to 10586.420