[SOLVED] Possible issue with Core i7 8700K Clock speed fluctuation on Idle.

NMRH

Honorable
Aug 4, 2014
12
0
10,510
Hello comunity,
I've build a new Z370 Rig this past week, yesterday, I found something odd while checking CPU-Z.
It just wont maintain low clock speeds; it doesn't matter if there's apps on the background or not; it will keep on spiking to the roof with 4.6 ~ 4.7GHz at multiple moments.

It also doesn't matter if the usage is the lowest possible or not, as this was observed while 0 ~ 4% Usage.

I've been into PC gaming for almost 15 years now, I've never seen something like this on adptive clock speed CPUs in the past. I've seen many floating around 800~960MHz up to 2.4~2.6GHz but never this high, its just out of this world to me.
typical Idle voltage - 0.720v up to 0.880v ( 0.728v most time )
typical load voltage - 1.115v up to 1.36v(Peak) during Cinebench R15 (1.120v~1.128v most time/runs)
BIOS voltage - 1.048v


System Specs:
CPU: 8700K
MoBo: MSI Z370 SLI Plus (Latest BIOS/ Stock settings/ XMP enabled)
RAM: 2x8GB 3200MHz 16-18-18-38-2T
OS: Windows 10, updated to the latest build
All drivers Installed.

I would like to know if this is serious issue, and how to make it Idle properly, if thats even possible.
At this point I cant tell if I have a broke CPU, BIOS or something else; If any1 have the knowledge to help me out in someway, it would be great.
https://imgur.com/a/f43Q8xw
 
Solution
NMRH,

Most members experience the same problem with their 8700K that you've described. We see many of these threads every day. Since temperatures respond instantly to changes in load, most people express their concerns based on temperature spikes, while some, like yourself, express the problem in terms of load spikes. Nevertheless, it's the same problem, which is also shared by the 7700K and other high-end 7th and 8th generation...
First thing, have you set the Power mode to Balanced in Windows? I dont think you have a CPU problem as the vocore is smack dab in the right area...You can lower that later by setting an ofset...

Also check to see if MCE is enabled..
 

NMRH

Honorable
Aug 4, 2014
12
0
10,510


Hi, thx for replying.

Yes, "Balanced" was in fact enabled.
Balanced / Power Saving have a very similar behavior.
High Performance keeps all cores around 4.3~4.4GHz.

"Smack dab, meaning: in the middle of someting" - So this chip should have a pretty avg voltage, thx for the info. At least Im not frying it.
MCE should be disabled / XMP Enabled - As stated by two large icons in the BIOS main display.
Here, https://imgur.com/a/Xcb4NIK take a look at that amazing "Idle" clock speed graph. 0~4% usage most time, I just dont understand.
Maybe this is normal, it just dont feel like that, I guess. IDK.
 
Hi NMRH, Just took a look and it does look ok. My 8700K moves between 800 and upwards dempending on load but always seem to bounce between 100 and mid 2000's...Looking at your CPU Z it currently shows 2600 so I think it is fine and just adapting to loads... I notice you have Rainmeter installed as well so that can also be dynaically load the cpu is super short bursts...
 

NMRH

Honorable
Aug 4, 2014
12
0
10,510


Exactly, I agree with you, 800MHz up to mid 2000MHz it would be "normal".

On the original post you can see another print, the last part of the graph, was when I reach to the PC itself to take the print, the cock speed just go full bananas, doing nothing, I dont understand this.
I see… for the record, I've tried to turn off everything (yes, antivírus too) and keep doing the same.

Maybe its the nature of the beast, I've built more rigs than I can count, never to see a high performance cpu spiking to the heavens in "Idle". It makes no sense. I still think there's something wrong here.
 

CompuTronix

Intel Master
Moderator
NMRH,

Intel’s specification for Digital Thermal Sensor (Core temperature) response time is 256 milliseconds, or about 1/4th of a second, so Core temperatures increase and decrease instantly with changes in load.

As you're no doubt aware, 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, which should eventually settle.

Any software activity will show some percentage of CPU Utilization in Task Manager, where unnecessary Tray items, Startups, Processes and Services that contribute to excessive or continued spiking can be disabled. However, as the workload increases to 100%, the spike levels are overtaken and become obscured by the load. Nonetheless, here's what's different about your 8th Generation processor:

Beginning with 6th Generation processors, Intel 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.

Since 7th and 8th Generation Speed Shift is twice as fast as 6th Generation, some users complain of Core temperature spikes, which in worst case scenarios, can also cause fluctuations in fan RPM at idle. Motherboard manufacturers are developing BIOS fixes that include separate SpeedStep and Speed Shift settings with more flexible fan curves and time delay options.

There's nothing wrong with your 8700K; it's behaving quite normally as per design.

CT :sol:
 

NMRH

Honorable
Aug 4, 2014
12
0
10,510

Hi, thx for replying, it was very informative and helpfull

Well, I've conducted some testing in last 2 days just to find out the truth.
Cause "the truth it's out there" right ?
Thermals ? thats ok, but I've never talked about thermals. :??:

After a fresh Windows re-instal this was what I found.

First boot (20minutes idle):
Windows report - 0,80GHz ~ 1.6GHz
CPU-Z report - 799MHz ~ 1.6 GHz

After all Drivers instaled (30minutes Idle):
Windows report - 0,78GHz ~ 1.6GHz
CPU-Z report - 799MHz ~ 1.6 GHz

After all Windows updates instaled + All background apps (20 minutes Idle):
Windows report - 0.78GHz ~ 2.7GHz
CPU-Z report - 799MHz ~ 2.7 GHz

After upgrading Windows 10 build version from 15xx to 1803 (24 minutes Idle):
Windows report - 1.6GHz ~ 3.5 GHz
CPU-Z report - 799MHz ~ 4.6 GHz

So, this is what's actually happening, W10 April 2018 upgrade broke it.
Windows report went crazy / incorrect and the cpu is now reporting spikes to the heavens (for no good reason ?).
Example, just moving the mouse around ( not even clicking, just moving ) locks the CPU to 4.4GHz until I stop; as seen in this print - https://imgur.com/a/vnJ48ND - under Profile 1 in MSI AB.
Why ? Why do I need 4.4GHz to move the mouse (specifically on build 1803) ?
I've never seen something like this. I may accept it, but I still don't get it, makes no sense.

It may be normal, but it feels wrong, very wrong.
 

CompuTronix

Intel Master
Moderator
NMRH,

Most members experience the same problem with their 8700K that you've described. We see many of these threads every day. Since temperatures respond instantly to changes in load, most people express their concerns based on temperature spikes, while some, like yourself, express the problem in terms of load spikes. Nevertheless, it's the same problem, which is also shared by the 7700K and other high-end 7th and 8th generation processors.

There's a 74 page thread on Intel's Forum regarding this very issue - https://communities.intel.com/thread/110728?start=1095&tstart=0 - The title is a bit misleading as it doesn't accurately characterize the problem, but as the thread progresses, the actual problem becomes more clear.

As I attempted to explain to you in my above post, the root of the problem is Speed Shift, which is driver-integrated into Windows 10. As illustrated in the above chart, Intel implemented this technology to save power over time, by greatly reducing the time it takes to execute and complete processor tasks, then quickly return to idle. Since Intel has made impressive strides in reducing power consumption and increasing efficiency, the development of power saving features such as Speed Shift result in considerable energy savings.

However, users who observe Speed Shift's behavior graphically rather than numerically, such as you and I, whether thermal spikes or load spikes, are almost always taken aback by how rapid, pronounced and seemingly continuous the spiking actually is. All processors inherently produce load and thermal spikes when executing various workloads, especially those which are heavier with greater fluctuations.

As M$ continues to implement "features" they insist we "need", the additional background activities increase spiking. Nonetheless, when we run heavy workloads that approach 100% TDP, spiking from lesser background loads becomes obscured. Spiking can not be eliminated, only dampened and minimized by improving cooling, reducing core voltage, disabling background startups, processes and services, and by delidding.

Does this explanation make more sense?

CT :sol:
 
Solution

NMRH

Honorable
Aug 4, 2014
12
0
10,510


Sure, Im getting your point. I do understand what's happening, its still very troublesome tho.

W10 Build 15xx everything works fine, Build 1803 everything went full bananas.
CPU in now capable of dealing with tasks/work faster (on demand) - that's great !
Despite addressing those tasks faster, it will also require higher clocks than before - so what's the point ?
Where are my savings ?

Before build 1803 I could do anything, literaly, on idle, it would never go above 2.7GHz (with some rare spikes to 3.xGHz), with a max voltage of 0.786v (usually 0.728v)
Although on Build 1803, with all those crazy high clocks, on Idle, 0.8 ~ 0.9v are now common.
So, where are my savings ? Im saving more with higher voltages( and more often), thats a true miracle; I'll give them that.

All this is a big mess, Im sure that the almighty Intel will figure it out, actualy they need to figure out many things, fast…

Im gonna pick your reply as Solution cause this is a dead end.
I just want to say thank you for your time and for sharing your knowledge.
Truly appreciated.