Ok so I switched from AMD to Intel and now I'm having a scary issue. I have a i7 6700k Stock with an EVGA Z170 Classified K and HyperX Savage DDR4 Ram. The cooler I'm using is a H100i and I know it's seated properly cuz I took it off, cleaned the thermal paste and reseated it just fine. More often than I'd like my computer will boot and the CPU will downclock itself to 800mhz. I've done some reading and there was a few people saying the board could have a faulty sensor? Anyways. This gets tedious and happens far too often to be "ok". Second issue I'm having is my computer does this... weird thing sometimes when I turn it on, it'll power for 1 second, shut down and then restart. Doesn't feel normal to me. Any suggestions? If you need more info let me know.
 
Things I've tried: Reset CMOS. Disabled the Step thingy in BIOS. Reseat RAM, GPU, even formatted.
Note: I don't think it's thermal throttle. All my temps read just fine and the motherboard temp LED reads 22 degrees.

Nanobytez
Ok so I switched from AMD to Intel and now I'm having a scary issue. I have a i7 6700k Stock with an EVGA Z170 Classified K and HyperX Savage DDR4 Ram. The cooler I'm using is a H100i and I know it's seated properly cuz I took it off, cleaned the thermal paste and reseated it just fine. More often than I'd like my computer will boot and the CPU will downclock itself to 800mhz. I've done some reading and there was a few people saying the board could have a faulty sensor? Anyways. This gets tedious and happens far too often to be "ok". Second issue I'm having is my computer does this... weird thing sometimes when I turn it on, it'll power for 1 second, shut down and then restart. Doesn't feel normal to me. Any suggestions? If you need more info let me know.
 
Things I've tried: Reset CMOS. Disabled the Step thingy in BIOS. Reseat RAM, GPU, even formatted.

So if I understand this correctly your CPU is down clocking and you do not want it to do that? If that is said issue change your power settings (In control panel)  to High performance and your CPU will stay @ max clock all the time no matter what you do.  As far as your other issue with you boot up, I have no idea. I do have an old P55 FTW that does this same procedure though. Hopefully the MOBO masters will have a solution or verify this is just the way they boot. GL!!

The downclocking it's doing isn't the normal "downclock when idle". The CPU runs at 800mhz consistently no matter what load I put on it. My power settings are on High Performance.

Download EVGA E-Leet software and run it. Download the Heaven Benchmark from Unigine. When you first open the Heaven Benchmark untick the box that says full screen. Run that benchmark (in windowed mode). Then launch E-leet and check the CPU speed. The speed should bump up after about 5 seconds or so.
 
Alternatively if the heaven benchmark won't run in a smaller mode just take your mouse curser and drag the screen down a bit so that it is still running and look at E-Leet and the CPU core speed.
 
On my X99 motherboard the idle speed is 1200. When running the benchmark the speed bumps up to about 3400.

Another alternative is that if you are running the folding at home program from Stanford University run the E-Leet EVGA program and the CPU core speed should be at maximum core speed.

The issue isn't that the CPU isn't getting load, it's that the CPU randomly says "Hey, today, instead of 4ghz, lets run at 800mhz!" Adding load doesn't change that for me unfortunately. I have to restart a few times to fix it. Also a side note. I've NEVER seen a BIOS to register any idle frequency before and my bios often shows 800mhz and sometimes 4ghz.
 
At the time of this writing it's showing 4.01ghz, but I remember in my bios I had the multipliers set the 42. So there's that bit of weirdness.
 

Try disabling eist & all cpu c-states.

Sajin
Try disabling eist & all cpu c-states.

Done and done, I'll keep you posted if anything else happens. Any clue on the weird restart issue I'm having?

The restart issue is definitely related to the motherboard bios itself. Faulty overclocks can cause that same symptom. Try the secondary bios on the motherboard to see if it has the same problem.

There's no overclock and it's default aside from the steps you gave me. The other boots painfully slow for some odd reason.