help NEED HELP WITH CPU SPEED

[modestep15]

Hi my i7 8700k has randomly started rapidly fluctuating for no apparent reason. I've overclocked it to 4.7GHz a few months ago and a few hours a ago it has been fluctuating from 4.7Ghz all the way down to 1Ghz and everything in between. It is fluctuating whilst idling and when I play games it continues and my whole pc freezes. My temps are around 37c which are normal and I have no idea why it is doing this, any help would be appreciated.

 

Thanks

 

Edit: its is now fluctuating around 1-2GHz

 

Edit #2: my CPU temp has risen to 80c+ (from mid 30s) at idle and I haven't done anything to cause this

[Jurrunio]

Try start Prime95 smallFFT test, and monitor temps. If it goes higher or even shutdown then the CPU is overheating, most likely because the thermal paste dried up.

[modestep15]

5 minutes ago, Jurrunio said:

Try start Prime95 smallFFT test, and monitor temps. If it goes higher or even shutdown then the CPU is overheating, most likely because the thermal paste dried up.

I'm doing the test now jsut wanted to add that my pc also randomly restarts without warning and comes back

[modestep15]

13 hours ago, Jurrunio said:

Try start Prime95 smallFFT test, and monitor temps. If it goes higher or even shutdown then the CPU is overheating, most likely because the thermal paste dried up.

This is what it is doing

[Jurrunio]

2 hours ago, modestep15 said:

This is what it is doing

what board is this?

[modestep15]

1 hour ago, Jurrunio said:

what board is this?

Asus ROG Maximus X Hero

[Jurrunio]

Just now, modestep15 said:

Asus ROG Maximus X Hero

maybe power management settings in Windows is in power save? Set that to high performance or balanced.

[modestep15]

23 minutes ago, Jurrunio said:

maybe power management settings in Windows is in power save? Set that to high performance or balanced.

Just checked and it is already on balanced, the clock speed on my CPU is fine for about 5-10 mins when it first boots then it starts fluctuating like crazy.

[Jurrunio]

3 minutes ago, modestep15 said:

Just checked and it is already on balanced, the clock speed on my CPU is fine for about 5-10 mins when it first boots then it starts fluctuating like crazy.

Try blow air to the VRM heatsinks. Also make sure the core voltage isnt too high

[modestep15]

10 minutes ago, Jurrunio said:

Try blow air to the VRM heatsinks. Also make sure the core voltage isnt too high

All of my voltages (including core) are set to auto, I had overclocked my CPU to 4.7GHz which was the turbo clock so I didn't have to change the voltage. I've reset the clock speed to auto and the only voltage that isn't auto is the dram, for some reason it says 1.344w and when I try to change it to that is auto sets it a 1.500w and there's no auto option.

[modestep15]

27 minutes ago, Jurrunio said:

Try blow air to the VRM heatsinks. Also make sure the core voltage isnt too high

I've launched a game and after resetting the overclock to auto it's around 4.3Ghz constant

[_Hustler_One_]

4 hours ago, modestep15 said:

All of my voltages (including core) are set to auto

This is most likely the problem. this CPU turbo boost is up to 4.3GHz all core and 4.7GHz single core. Set the clock speed manually at 4.7GHz and turn off the auto, and set it manually between 1.15v-1.2v for that 4.7GHz, in my case, for 4.7GHz it needs 1.17v and I locked all cores at 4.7GHz with fixed 1.17v, stress tested it stable.