Dynamic overclocking? I7-9700k

[xvladyo]

Hi,

 

I am running a i7-9700k on a z390 msi mpg gaming pro carbon ac mb and am currently fixed oc on 4.8GHz. 

 

This leads to relatively high idle temps and I was thinking about a dynamic overclock since windows doesn‘t need 4.8GHz on 8 cores to just be on, does it? 

 

So the question is: dynamic overclocking. Recommended or not? If so, how can I achieve it? 

 

I tried once to put some of the settings in my bios to dynamic and the powermode to balanced instead of performance but it kept camping at a fixed rate. 

 

What do you guys think? 

 

[fabafaba]

If you're not doing some crazy dry ice or LN2 overclocking, you definetly don't want your CPU to run at full oomph all the time. Your problem sounds like EIST (or Enhanced Intel SpeedStep) is still disabled, and make sure in both the advanced bios and oc mode because otherwise that option may be hidden.

[Brooksie359]

Honestly I would keep it at stock. 4.8ghz on all cores isn't really an overclock when stock clocks are basically right there and your single core boost is higher. 

[unclewebb]

If you have a stable overclock and if you want your CPU to down clock when idle, go into the bios and enable the C3 / C6 / C7 C states.  When an unused core has nothing to do, it will disable itself from the voltage rail and it will disable itself from the internal clock so it will be running at 0 MHz and 0 Volts.  If you do not have a lot of background junk running on your computer, individual cores can spend over 99% of their idle time in C7.  This is the easiest and best way to reduce power consumption and idle temps.  The mainstream monitoring apps cannot show you what a core is doing when it is in C7.  Keep an eye on idle temps and idle power consumption instead.  

 

[xg32]

just using an offset voltage will get it to run at 800mhz idle on most motherboards.

[unclewebb]

On an 8 core CPU, when lightly loaded, almost all of the cores are going to be inactive because they have no tasks that need to be completed.  800 MHz sounds good but why not use C states and force the individual idle cores to run at 0 MHz instead?

 

The CPU multiplier is shared with all active cores.  When running a single threaded task, all 8 cores are going to be forced to run at full speed.  With C7 enabled, you have one core that needs to be at full speed while the other 7 cores at any moment in time will be at 0 MHz.  Give it a try and see which method gives you lower temps and better off idle performance.  

[xvladyo]

9 hours ago, Brooksie359 said:

Honestly I would keep it at stock. 4.8ghz on all cores isn't really an overclock when stock clocks are basically right there and your single core boost is higher. 

Well stock is 3.6 GHz and 4.8 is kinda a little bit more, isn‘t it? 

[xvladyo]

7 hours ago, unclewebb said:

If you have a stable overclock and if you want your CPU to down clock when idle, go into the bios and enable the C3 / C6 / C7 C states.  When an unused core has nothing to do, it will disable itself from the voltage rail and it will disable itself from the internal clock so it will be running at 0 MHz and 0 Volts.  If you do not have a lot of background junk running on your computer, individual cores can spend over 99% of their idle time in C7.  This is the easiest and best way to reduce power consumption and idle temps.  The mainstream monitoring apps cannot show you what a core is doing when it is in C7.  Keep an eye on idle temps and idle power consumption instead.  

 

I don‘t have that much of an idea about overclocking yet, but when I read this I kinda hear „unstable“

[xvladyo]

Thanks for the answers, I will play around a little bit and report back if anything worked.

[Brooksie359]

5 hours ago, xvladyo said:

Well stock is 3.6 GHz and 4.8 is kinda a little bit more, isn‘t it? 

3.6 is the base clock. It won't run at that unless it is at idle. In reality it will all core boost to something like 4.7.