Question I7-8700k Core Voltage oscillate between 0.672 V to 1.032 V (Idle) without OC

Oct 28, 2019
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Hi Everyone,

My I7-8700k is not working normal, so I never OC my CPU and since I bought this CPU, when i open the CPU-Z i can see the voltage and core speed oscillanting all the time. I had a Z370 AORUS GAMING 7 and i am not sure if i can set up something into the BIOS. Anyone already had this kind of issue ?

I have uploaded some images from CPU-Z.

Image 1
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Image 4
 
Voltage fluctuations from low idle to high load ALWAYS fluctuate under normal circumstances unless you SPECIFICALLY configure your built to NOT do so, and even then, there will still be SOME variation. It is normal, like I said.

What, EXACTLY, aside from the changing core speed and voltage, do you think is not working correctly?
 
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Oct 28, 2019
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Voltage fluctuations from low idle to high load ALWAYS fluctuate under normal circumstances unless you SPECIFICALLY configure your built to NOT do so, and even then, there will still be SOME variation. It is normal, like I said.

What, EXACTLY, aside from the changing core speed and voltage, do you think is not working correctly?

I totally agree with you, but my scenario is a bit different, i would say that the voltage fluctuations in the idle mode for me is not normal. is it? and also my temperature follow the same problem, is not stable in the idle mode (temp fluctuation from 37 ° C to 46 ° C ).
 

AshMetalRaf

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Sep 19, 2018
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Yeap. I have tried too, the same issue :(

It is so stranger because once i have this kind of problem the temperature between core0 to core5 never been stable :(.
I can confirm it's normal core voltage on both my computers. However the temperature is odd..mine is at 39c-40c on all cores though the range from 37c to 46c is average CPU temperature and nothing to worry about unless it exceeded 50c on idle.
 
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Honestly, unless you are in a stripped down environment like safe mode, there really IS no such thing as "idle". There is always something going on, and even if it seems like nothing is going on for a few seconds, unless you have taken careful steps to completely minimize ALL background processes and startup programs to only those that are essential, there will always be some kind of processes starting, stopping, waiting for triggers, performing tasks, etc.

Core and package temps at "idle", meaning YOU are not intentionally running anything, no browser windows, all non-essential processes like game loaders in the tray, disk optimization (Automatic defragement/TRIM), system restore, either exited, ended or service killed, will STILL result in many background processes running. Just open task manager and browse through the Processes tab to get an idea. So, even then, if you have very minimal processes running and NEAR zero CPU resources being used, you will still usually see significant fluctuations in various core speeds/usage, temperatures going up and down, voltage changing based on core clock changes, etc.

Your numbers STILL seem normal to me. Things like Windows checking for updates, system restore making restore points, disk optimization running defragmenter or TRIM, OTHER programs, games and applications doing their thing checking for updates, browsers checking for updates, plus all the hidden Windows processes that are doing their thing behind the scenes, means you will never see a CPU just sitting there on a zero fluctuation 800mhz clock for very long, and when the clock goes up the voltage goes up to keep things stable. And when the voltage goes up and the clock goes up, the temperature goes up in kind. All very much normal.

Now, if you start seeing HIGH CPU USAGE for no reason, or processes in Task manager that you can't account for or find any information about, then it's time to start looking for infections or rogue programs. As it stands, there's a few things I'd do.

One, make sure your motherboard BIOS is completely up to date, unless you have a very good reason for NOT installing a specific BIOS version. That is rare, but it happens from time to time.

Two, make sure you have MANUALLY installed all of the relevant drivers for your motherboard from the motherboard product page on the manufacturers website.

All of these should be installed unless there is a good, specific reason for not doing so such as known conflict problems between a hardware specific driver and some other hardware on your system.

Install in THIS order:

Z370 Aorus Gaming 7 chipset drivers:

https://download.gigabyte.com/FileList/Driver/mb_driver_chipset_300ser_infupdate_10.1.17969.8134.zip

Realtek driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_audio_realtek_8586.zip


Install BOTH of these LAN drivers, however, I recommend that you USE the Intel network adapter as I believe it is the better of the two. So figure out which is which and plug your ethernet cable into the Intel ethernet socket.

Killer LAN driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_lan_killer_2.0.1125.zip

Intel LAN driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_lan_intel_23.5.zip


ASMedia USB 3.1 driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_usb31_asm_300series.zip


And I recommend that you update to the F14 BIOS version.
 
Oct 28, 2019
4
0
10
Honestly, unless you are in a stripped down environment like safe mode, there really IS no such thing as "idle". There is always something going on, and even if it seems like nothing is going on for a few seconds, unless you have taken careful steps to completely minimize ALL background processes and startup programs to only those that are essential, there will always be some kind of processes starting, stopping, waiting for triggers, performing tasks, etc.

Core and package temps at "idle", meaning YOU are not intentionally running anything, no browser windows, all non-essential processes like game loaders in the tray, disk optimization (Automatic defragement/TRIM), system restore, either exited, ended or service killed, will STILL result in many background processes running. Just open task manager and browse through the Processes tab to get an idea. So, even then, if you have very minimal processes running and NEAR zero CPU resources being used, you will still usually see significant fluctuations in various core speeds/usage, temperatures going up and down, voltage changing based on core clock changes, etc.

Your numbers STILL seem normal to me. Things like Windows checking for updates, system restore making restore points, disk optimization running defragmenter or TRIM, OTHER programs, games and applications doing their thing checking for updates, browsers checking for updates, plus all the hidden Windows processes that are doing their thing behind the scenes, means you will never see a CPU just sitting there on a zero fluctuation 800mhz clock for very long, and when the clock goes up the voltage goes up to keep things stable. And when the voltage goes up and the clock goes up, the temperature goes up in kind. All very much normal.

Now, if you start seeing HIGH CPU USAGE for no reason, or processes in Task manager that you can't account for or find any information about, then it's time to start looking for infections or rogue programs. As it stands, there's a few things I'd do.

One, make sure your motherboard BIOS is completely up to date, unless you have a very good reason for NOT installing a specific BIOS version. That is rare, but it happens from time to time.

Two, make sure you have MANUALLY installed all of the relevant drivers for your motherboard from the motherboard product page on the manufacturers website.

All of these should be installed unless there is a good, specific reason for not doing so such as known conflict problems between a hardware specific driver and some other hardware on your system.

Install in THIS order:

Z370 Aorus Gaming 7 chipset drivers:

https://download.gigabyte.com/FileList/Driver/mb_driver_chipset_300ser_infupdate_10.1.17969.8134.zip

Realtek driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_audio_realtek_8586.zip


Install BOTH of these LAN drivers, however, I recommend that you USE the Intel network adapter as I believe it is the better of the two. So figure out which is which and plug your ethernet cable into the Intel ethernet socket.

Killer LAN driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_lan_killer_2.0.1125.zip

Intel LAN driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_lan_intel_23.5.zip


ASMedia USB 3.1 driver:

https://download.gigabyte.com/FileList/Driver/mb_driver_usb31_asm_300series.zip


And I recommend that you update to the F14 BIOS version.

I really appreciate your concerns. I am going to studding a little bit more regarding how the intel processor works to try to figure out why that kind of fluctuation happens and I totally agree when you said the computer never will be "Idle" because there are a lot of instruction to have the OS operating, but for me voltage fluctuation must cause clock fluctuation and also high temp it is not normal. I already update my mobo and still the same.

Thanks again :)
 

CompuTronix

Intel Master
Moderator
[B]Anselmi[/B],

On behalf of Tom's Moderator Team, welcome aboard!

If you're not accustomed to closely monitoring how workloads affect CPU Utilization patterns, Core voltage, power consumption and thermal behavior, then although it might seem peculiar, the fluctuations are always there but you simply haven't notice. As my esteemed colleague, Darkbreeze, has explained so thoroughly, "spikes" or "fluctuations" in workload and Core temperatures are normal and expected.

Core temperatures respond instantly to changes in load.

Intel’s specification for Digital Thermal Sensor (DTS) response time is 256 milliseconds, or about 1/4th of a second. Again, just as Darkbreeze explained, since Windows has dozens of Processes and Services running in the background, it’s normal to see rapid and random Core temperature “spikes” or fluctuations, especially during the first few minutes after startup. Any software activity will show some percentage of CPU Utilization in Windows Task Manager, where unnecessary Tray items, Startups, Processes and Services that contribute to excessive spiking can be disabled.

Moreover, 6th Generation processors introduced "Speed Shift" technology in Windows 10, which responds much faster to changes in workload than "SpeedStep" due to having many more Core speed and Core voltage transition levels. This allows the processor to more rapidly complete brief tasks then quickly return to idle, which reduces overall Power consumption and increases efficiency.



Since 7th through 9th Generation Speed Shift is twice as fast as 6th Generation, some users complain of Core temperature spikes which can also cause fluctuations in fan RPM at idle. To address those issues, motherboard manufacturers have implemented BIOS updates that include separate SpeedStep and Speed Shift settings with more flexible fan curves and time delay options.

The spikes in CPU Utilization and Core temperatures are quite normal and expected, and are simply due to the processor's ability to very rapidly respond to fluctuations in Windows foreground and background activities.

Idle is defined as minimum processor activity at 1% CPU Utilization in Windows Task Manager, which is when your rig is undisturbed and at a "quiet" idle. This means hands off; no programs or screen saver running and off line. No Folding or SETI or "tray-trash" running in the background. The best way to observe and comprehend the nature of workloads, voltage and thermal behaviors is on a graph. Here's a screenshot taken at just the right moment when Windows 10 showed a clean and quiet idle:



Unless Windows and your installed software is kept cleaned, groomed and polished, which the vast majority of users don't bother to do, then you won't see the clean baseline idle shown above.

Even when a processor is in a state of minimum activity, there will still be background activities taking place that will cause fluctuations. In a best-case scenario, which is shown on an i7-8700K in the example above, notice how the moderate spike in Wi-Fi activity coincides with the low and subtle spike in CPU Utilization. Almost all software workloads fluctuate, which drives clock speed and Core voltage, which in turn drives power consumption (watts) and Core temperatures. These are all completely normal and expected behaviors, and are nothing to be concerned about.

If you'd like to get yourself up to speed on this topic so you can put your mind at ease, we have a guide you can read: Intel Temperature Guide. See Sections 4 and 13.

Once again, welcome aboard!

CT :sol:
 
Let me guess: at 800 MHz, it's low voltage, and at 1300-2100 Mhz, it's higher, and, at 4000-4700 MHz,.... it's even higher yet? :)

All classic symptoms indeed of ....100% normal operation in Balanced power mode, where we save power when merely loafing on the desktop with Wordpad or Solitaire, surfing ....websites, and, ramp up to 4.4 GHz on all cores when gaming or rendering...