Confused about temperatures with my 7700K 5GHz 1.328V

Hello!

New to this forum but I've been trying to learn/find an answer all day about my KabyLake 7700K.

First I'll list my specs, just so everything is known:

CPU: 7700K @ 5GHz w/ 1.328 vCore
MOBO: MSI Z270 Gaming Pro Carbon
GPU: 970 GTX (upgrading, soon).
MEM: Corsair Vengeance LPX DDR4 3200MHz
COOLING: Corsair H100i V2 w/ pre-applied thermal paste

http://www.userbenchmark.com/UserRun/3051401



Ok, so firstly these are the only things I have changed in BIOS:

CPU Clock: 50 (5GHZ)
EIST: Disabled
Extreme Memory Profile: Enabled
CPU Core Voltage: 1.325 (1.328V displaying in BIOS) - CPU SA Voltage: 1.200 (1.208V displaying in BIOS as shown in the image after Core Voltage) - This value was set to AUTO previously, and over 1.3V
CPU IO Voltage: 1.150 (1.160V displaying in BIOS as shown in the image after Core Voltage) - This value was set to AUTO previously, and over 1.3V

Now - originally that is all I had changed, and my temps were a little too high for my liking though.

So I reached out for help on a different forum called overclock, and a user recommended I change this setting below:

CPU PLL OC Voltage - It was set to AUTO, and he told me to change it to 1.150. My motherboard says default is 1.2, and I can use anywhere from 0.6 to 1.5 (that's what it says on the "HELP" on the right hand side).

After changing this setting, my temps dropped 10-15c. Now when gaming they only hit 65 maximum.

I was then told by two other users of the same forum that it is just the dts sensors reporting FALSE readings, or so they believe. Now, I find this strange as I can't imagine any bios setting would do such a thing without ANY documentation anywhere on the internet (I've been looking all day and seeking as much help as possible).

Now, my overclock is stable, or at least it is stable right now. With these current settings, I only ran a few stresses, x264 for over an hour, no crashes, gaming all day with no crashes. Obviously it could crash tomorrow, next week and so on but for now, we're good.

I am concerned however about these claims of it reporting FALSE temperatures since changing that setting off AUTO to 1.150.

Help would be very much appreciated, and/or some understanding of this setting. The only information I have found on it so far (which is old, and possibly false, also is here):

"CPU PLL Voltage Override (Overvoltage): What the Heck does it do?
So I asked that question to an Intel Overclocking Engineer his explanation was roughly: We went through the BIOS settings trying to find setting that if changed could help overclock our CPUs further. We came across this setting. Think of the CPU PLL voltage as a voltage that is provided to the CPU, but then “clipped” down to an approximate voltage. No matter what that input is whether 1.3v or 1.9v it is clipped (hypothetically let’s say 800mv after clipping (he didn’t say how much)) that way other devices can use the PLL voltage and clip to what they need. The CPU PLL Overvoltage allows for less clipping of that voltage. It can also reduce the lifespan of the CPU, but nothing noticeable."

"CPU PLL Voltage: Sets the voltage for the internal phase locked loop. The role of the PLL is to ensure that the output clock of the internal processor frequency synthesizers maintains phase coherency with the reference clock signal (supplied from a clock generator located within the PCH). "


Thanks for any help;

Richard

So you lowered the PLL voltage to reduce temps instead of raising it as the latter quotes suggest to do for a more stable overclock?

trents said:

So you lowered the PLL voltage to reduce temps instead of raising it as the latter quotes suggest to do for a more stable overclock?

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Not sure I see the relevance? My vcore was auto too at like 1.38 but that was too high so I lowered it.

Auto doesn't mean it can't be lowered. Also my motherboard didn't say what it was set to value wise it just said auto.

CPU PLL voltage is not the same as core voltage. You quoted all these people on other forums who were talking about changing the PLL voltage, not core voltage. What you did lower to 1.325 seems to be the core voltage.

So the only relevant questions are: after you lowered your vcore to 1.324 are your temps under control? And is the system still stable.? Have you stress tested the system to check for stability?

You must take the core voltage off of auto in order to change it, which I assume you discovered. I guess what confuses me is why when included that whole section in your first post about lowering and raising the PLL voltage.

trents said:

CPU PLL voltage is not the same as core voltage. You quoted all these people on other forums who were talking about changing the PLL voltage, not core voltage. What you did lower to 1.325 seems to be the core voltage.

So the only relevant questions are: after you lowered your vcore to 1.324 are your temps under control? And is the system still stable.? Have you stress tested the system to check for stability?

You must take the core voltage off of auto in order to change it, which I assume you discovered. I guess what confuses me is why when included that whole section in your first post about lowering and raising the PLL voltage.

Click to expand...

No, you have misunderstood my post.

trents said:

CPU PLL voltage is not the same as core voltage. You quoted all these people on other forums who were talking about changing the PLL voltage, not core voltage. What you did lower to 1.325 seems to be the core voltage.

So the only relevant questions are: after you lowered your vcore to 1.324 are your temps under control? And is the system still stable.? Have you stress tested the system to check for stability?

You must take the core voltage off of auto in order to change it, which I assume you discovered. I guess what confuses me is why when included that whole section in your first post about lowering and raising the PLL voltage.

Click to expand...

I will explain easier for you.

The core voltage barely changes my temps, my system has been stable for 2-3 days, no issues.

My temps were about 8-15c higher when the CPU PLL voltage was set to "AUTO" (it didn't display what value this was using, though).

In my bios it says:

DEFAULT PLL: 1.2
MINIMUM: 0.6
MAXIMUM: 1.5

I changed it to 1.10 - the temps dropped dramatically, then It became unstable during testing on x264 stress test.
I changed it to 1.15 - the temps were still much better than AUTO and it has been stable.

What I am trying to confirm is: Some people CLAIMED changing the PLL CPU Voltage can affect the reading of the sensors, yet they could not provide any proof, so I am trying to find answers elsewhere.

No idea on what it can do to the sensors...I haven't seen cpu pll lower temps like that though. Vcore drops temps way more than pll.

How about you post a screenshot of the bios (f12, save to usb, then host here at the forums) so we can see what's going on.

EarthDog said:

No idea on what it can do to the sensors...I haven't seen cpu pll lower temps like that though. Vcore drops temps way more than pll.

How about you post a screenshot of the bios (f12, save to usb, then host here at the forums) so we can see what's going on.

Click to expand...

Nothing to show, but here is someone doing it in windows so you can see what it does:

how does it instantly drop temp like that when he applies the number? Seems odd.

Yeah, the fact that it instantly drops would definitely lead me to believing its a false reading.
Which is a pretty crazy thought.

Haturee said:

Yeah, the fact that it instantly drops would definitely lead me to believing its a false reading.
Which is a pretty crazy thought.

Click to expand...

The same way that when you stop a prime95 test, it drops temperature instantly. Obviously that is load, and not volts, but less voltage, simply is less temperature.

I did a test:

It doesnt instantly tank like that. There is no drop in numbers. Its going from 7X right down to 6X at the exact time of the button click (change). Im still not believing that reading.

I think the PLL voltage drop lowers the voltage output on the Vcore sensor.

wingman99 said:

I think the PLL voltage drop lowers the voltage output on the Vcore sensor.

Click to expand...

You keep saying random stuff like this on several forums, yet you've not actually provided any evidence for anything you say. I'm not saying you're wrong, or right. But saying "I think" literally means nothing.

Here is why:

1.3 is the AUTO setting.
1.2 is the DEFAULT setting.

Now, if I move it to 1.4 and my temps go up, what would you say then? Enlighten me.

ritchiedrama said:

You keep saying random stuff like this on several forums, yet you've not actually provided any evidence for anything you say. I'm not saying you're wrong, or right. But saying "I think" literally means nothing.

Here is why:

1.3 is the AUTO setting.
1.2 is the DEFAULT setting.

Now, if I move it to 1.4 and my temps go up, what would you say then? Enlighten me.

Click to expand...

Try going up on PLL and down on Vcore and see if the temperature goes up.

wingman99 said:

Try going up on PLL and down on Vcore and see if the temperature goes up.

Click to expand...

What has this got to do with vCore? I think you need to look at what PLL is.

If I simply lower my PLL, I get lower temps. What do you think happens if I raise my PLL past the 1.3 (AUTO) setting? Please let me know.

ritchiedrama said:

What has this got to do with vCore? I think you need to look at what PLL is.

If I simply lower my PLL, I get lower temps. What do you think happens if I raise my PLL past the 1.3 (AUTO) setting? Please let me know.

Click to expand...

PLL (Phase-locked loop) has noting to do with actual core temperature.

Automobile race analogy

For a practical idea of what is going on, consider an auto race. There are many cars, and the driver of each of them wants to go around the track as fast as possible. Each lap corresponds to a complete cycle, and each car will complete dozens of laps per hour. The number of laps per hour (a speed) corresponds to an angular velocity (i.e. a frequency), but the number of laps (a distance) corresponds to a phase (and the conversion factor is the distance around the track loop).

During most of the race, each car is on its own and the driver of the car is trying to beat the driver of every other car on the course, and the phase of each car varies freely.

However, if there is an accident, a pace car comes out to set a safe speed. None of the race cars are permitted to pass the pace car (or the race cars in front of them), but each of the race cars wants to stay as close to the pace car as it can. While it is on the track, the pace car is a reference, and the race cars become phase-locked loops. Each driver will measure the phase difference (a distance in laps) between him and the pace car. If the driver is far away, he will increase his engine speed to close the gap. If he's too close to the pace car, he will slow down. The result is all the race cars lock on to the phase of the pace car. The cars travel around the track in a tight group that is a small fraction of a lap. https://en.wikipedia.org/wiki/Phase-locked_loop

Click to expand...

wingman99 said:

PLL (Phase-locked loop) has noting to do with actual core temperature.

Automobile race analogy

Click to expand...

If it has nothing to do with temperature, then why would it have anything to do with false readings, either?


But I'll ask for the third time:

My Setting: 1.150
Default: 1.2
AUTO: 1.3

What do you think happens if I use 1.35 or 1.4?

ritchiedrama said:

If it has nothing to do with temperature, then why would it have anything to do with false readings, either?


But I'll ask for the third time:

My Setting: 1.150
Default: 1.2
AUTO: 1.3

What do you think happens if I use 1.35 or 1.4?

Click to expand...

PLL (Phase-locked loop) clips the voltage frequency to the core temperature sensors when it is lowered.

I don't know what will happen give it a try.

wingman99 said:

PLL (Phase-locked loop) clips the voltage frequency to the core temperature sensors when it is lowered.

I don't know what will happen give it a try.

Click to expand...

Ok, and now can you provide me some evidence that it clips the voltage frequency to the core temp sensors?

Because if that's the case, going to 1.4 wouldn't INCREASE temps from 1.3

actually, yes it would man.. Because when you lower the number, it clips it. Raise it, and it provides a higher frequency voltage to the core temp sensor (if wingmans theory is correct). Give it a try. Let us know what happens.