I5-4670k Staying at Idle clock speed

[TheXLine]

I was having some problems with performance recently, so I opened up MSI Afterburner and CPU-Z and ran Prime95 to test how my CPU was doing. I noticed that neither my Core clock nor my voltage were changing from Idle, even at 100% load on a small FFT's test.
My Specs are:
CPU: I5-4670k
Mobo: Asus Z87-A
RAM: G.SKILL Ripjaws 2x4GB
HDD: WD Blue 1TB
GPU: GTX 650ti
PSU: Corsair CX600
Anything I can do here?

 

[GhislainG]

It probably is a setting in the BIOS; if you can't see what setting is not configured correctly, then reset it and then check if it resolved the issue.

 

[TheXLine]

It probably is a setting in the BIOS; if you can't see what setting is not configured correctly, then reset it and then check if it resolved the issue.

I reset the BIOS settings to default, and that doesn't seem to have fixed the problem.

 

[GhislainG]

Did you install any software that could control the CPU speed? What's the CPU temperature according to Intel Extreme Tuning Utility? Does it throttle?

 

[TheXLine]

Did you install any software that could control the CPU speed? What's the CPU temperature according to Intel Extreme Tuning Utility? Does it throttle?

Now this is interesting. I wasn't using IETU before, so I didn't know whether it was throttling. The CPU is running at 800 Mhz, at 100% load, 40 degrees Celsius, and according to IETU it's throttling at 100%. What could be causing that?
EDIT: It's also throttling at 100% even when not doing anything other than looking at IETU

 

[GhislainG]

Properly installing the cooler should resolve the issue. If you are using the stock cooler, then check if all 4 pins are fully locked in place.