Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Highlighted
Community Manager
8,911 Views

7700K Temperature - CPU PLL OC Voltage - Need an Intel response:

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 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) - http://i.imgur.com/3W2CL4z.jpg http://i.imgur.com/3W2CL4z.jpg

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

Tags (2)
0 Kudos
22 Replies
Highlighted
Community Manager
892 Views

There has been two things done so far

One guy has used a thermal gun - and seems to have confirmed that it seems fine when lowering the CPU PLL that the temperatures do drop, but a thermal gun in this scenario is not the height of accuracy.

Someone else did a write up here:

"I would like to go back to PLL OC voltage issues. I'm an owner of MSI Z270 M5 mainboard and 7700k CPU. I started a new thread some time ago (http://www.overclock.net/t/1621111/i7-7700k-temps-vs-ram-speed-on-z270-mainboard http://www.overclock.net/t/1621111/i7-7700k-temps-vs-ram-speed-on-z270-mainboard) concerning this matter.

Anyway, now my CPU is working at 4.7Ghz with 1.25/1.26 core voltage, 3200Mhz memory (dual sticks, 1.344V), some manually set voltages, including PLL OC set at 1.17V.

It's completely stable, realbench doesn't go over 80/81 degrees.

I'm only sure that PLL OC voltage doesn't affect the CPU performance. The question is, as many stated, if the temperature sensors show fake readings.

I asked MSI if it's possible, describing my problem really precisely, after many days of waiting they responded and sent me an UEFI screenshot showing where I can change the value of PLL OC voltage. I don't even know what to think about it. My dog would be probably more helpful than their support guys.

Today I tried to analyze the temps issue. Someone pointed out that even if PLL OC voltage is able to broke the CPU sensors readings, mainboard CPU temp sensor should be independent. Of course it's only our guess, nobody knows for sure.

I've checked CPU cores temps & MB CPU temp for PLL OC voltage 1.13, 1.17 (my setting), 1.2 (default), 1.25 and 1.3 (it's auto value if memory is OCed to 3200Mhz) in load and idle scenarios (using prime95 26.6 small FFT).

Here's the load scenario chart:

http://i.imgur.com/SOcEEsd.png

 

and here's the idle scenario:

https://s7.postimg.org/ehu7k9v9n/Overclock_2.png

 

As you can see the temps really increased with higher PLL OC voltage value and you can see that the hottest core temperature lines up with mainboard "whole CPU" reading.

But do you see the pattern here? The lower the PLL OC voltage the higher is the difference in separate cores temperatures.

Check this out:

With 1.13V the difference between the coldest and hottest core is from 10 to 16 degrees (depending on load/idle scenario). The difference is getting smaller for higher PLL OC voltage. With 1.3V the difference is 2 degrees on load and 1 degree on idle. ***?

For me it looks like lowering the PLL OC voltage can really break the readings, but not for the whole package. Or it's possible that the lower package temperature with lower PLL OC just results from lower core temps. Anyway, again, it's just guessing.

What do you think about it?

0 Kudos
Highlighted
Community Manager
892 Views

I have also now done my own testing:

 

0 Kudos
Highlighted
Community Manager
892 Views

Video of this in action (in the OS, but same applies in bios):

0 Kudos
Highlighted
New Contributor II
892 Views

Here is the Intel datasheet on PLL. http://www.intel.com/content/www/us/en/processors/core/core-technical-resources.html Intel® Core™ Processors Technical Resources

0 Kudos
Highlighted
Community Manager
892 Views

I request you stop following me onto every site you find about this topic, you have shown a huge misunderstanding of anything computer related and I find it worrying how much you keep "guessing" things; and provide no proof for any claims you have made either, wingman99.

Intel are the only people who can provide an insight here as to what is going on. I've opened up a support ticket with them so I don't have to read anymore of your nonsense.

0 Kudos
Highlighted
New Contributor II
892 Views

Hi RitchieDrama ,

First of all I want to tell you that Intel does not encourage overclocking. From the data sheets the normal Vcc PLL voltage is 1.0V with tolerance of + - 5%. You can find it at page 119 here:

http://www.intel.com/content/www/us/en/processors/core/7th-gen-core-family-desktop-s-processor-lines... Datasheet, Vol. 1: 7th Gen Intel® Processor Family for S Platforms

Have a nice day.

0 Kudos
Highlighted
Beginner
892 Views

Thnx for uploading a video for the matter.

May I ask what is the app you re using to change the PLL voltage? Cause I googled "voltage app" and nothing came on.

My MB: ASROCK Fatal1ty Z170 Gaming K4

http://www.asrock.com/mb/intel/Fatal1ty%20Z170%20Gaming%20K4/
0 Kudos
Highlighted
Beginner
892 Views

According to the electrical specifications on page 113 of the document below:

http://www.intel.com/content/www/us/en/processors/core/7th-gen-core-family-desktop-s-processor-lines... Datasheet, Vol. 1: 7th Gen Intel® Processor Family for S Platforms

VccPLL_OC power rail (which in the MSI Z270 M7 is set through the parameter CPU PLL OC Voltage) should be sourced from the VDDQ VR. The connection can be direct or through a load switch, depending desired power optimization. In case of direct connection (VccPLL_OC is shorted to VDDQ, no load switch), platform should ensure VccST is ON (High) while VccPLL_OC is ON (High).

VDDQ is the DRAM Voltage, which explains why when CPU PLL OC Voltage is set to auto, it takes whatever value the DRAM Voltage parameter is set to (by default 1.20V).

Interestingly enough, according to MSI, any voltage starting at 1.31V is not "safe" for CPU PLL OC Voltage. That means that anytime we enable XMP, VccPLL_OC is set to a non-safe value.

Still no clue why we get that core temperature difference.

0 Kudos
Highlighted
Community Manager
892 Views

Hello All,

Thank you to all the peer for the information provided.

RitchieDrama, I just wanted to let you know that Intel does not provide assistance for overclocking, so in this case the best thing is to wait for another community member to post similar experience or get more feedback on a different overclocking forum. Maybe you could try with https://forums.anandtech.com/forums/cpus-and-overclocking.5/ CPUs and Overclocking - AnandTech Forums or http://forums.extremeoverclocking.com/ EXTREME Overclocking Forums - Learn To Overclock Your PC Hardware. Like mentioned before, the normal Vcc PLL voltage can be found in the processors datasheet.

Regards,

Amy.

0 Kudos
Highlighted
Community Manager
892 Views

Overclocking has nothing to do with it, Amy.

0 Kudos
Highlighted
Community Manager
892 Views

RitchieDrama, I noticed that from your video that you are using a third-party software to change that value; have you tried getting in contact with their support in order to get more information regarding it?

Regards,

Amy.

0 Kudos
Highlighted
Community Manager
892 Views

It is the MSI software, but it's the same as doing it in the BIOS. It's just easier to show the change, with that video.

0 Kudos
Highlighted
Community Manager
892 Views

I just want to know; what did they say regarding that function? They should have a documentation that explains each function and their results from applying them.

Regards,

Amy.

0 Kudos
Highlighted
Community Manager
892 Views

RitchieDrama, hope the MSI support was able to provide more information,

If you need further assistance let us know.

Regards,

Amy.

0 Kudos
Highlighted
Community Manager
892 Views

MSI did say it'll help, Amy, however you need to address the issues with the 7700K, it isn't fair for the people who bought them, as much as you want to believe they're acceptable standard, they're not. The spiking issues everyone has, and de-lidding is the only way to fix the problem due to the bad TIM that was used during the process of making the 7700k.

Intel said they're aware, working on something 'apparently' -- but that can't be possible unless you're going to re-call all units and send new ones out/fix the TIM.

What's happening? What is the truth? Intel has a lot of people who support your CPU business, so at least help us back.

0 Kudos
Highlighted
Community Manager
892 Views

reply above was to you, forgot to reply to you directly.

0 Kudos
Highlighted
Community Manager
892 Views

RitchieDrama,

I just wanted to let you know that Intel is currently investigating the spiking behavior on certain Kaby Lake processors, at this stage the investigation is on going so no further details have been provided yet. Soon we will have some updates that will be posted on the following thread; /thread/110728 https://communities.intel.com/thread/110728.

 

Regards,

Amy.

0 Kudos
Highlighted
Community Manager
892 Views

Thanks for the responses, Amy.

Hopefully there will be some sort of solution soon or at least some information.

0 Kudos
Highlighted
Community Manager
892 Views

Hi RitchieDrama,

I am the Intel Support Community Manager and wanted to say thanks for your information on this. We are investigating reports of temp spikes on the 7700K. We don't have an answer yet as we are still running experiments but we're taking it seriously and trying to replicate it. I'll post an announcement on this forum to that effect.

Thanks,

Mary T.

Support Community Manager

0 Kudos