[SOLVED] Does it make sense, frequency wise, to combine Intel 12600K with Kingston DDR4 and Gigabyte Z690 UG motherboard?

[ChipsFries]

Hi everyone. Just curious if anyone has some comments for or against combining the following:

• Intel Core i5 12600K , whose frequency ranges from 2.9 GHz base up to 4.9 GHz max
• Gigabyte Z690 UG DDR4 motherboard
• Kingston KF440C19RB1/16 DDR4 RAM, whose available frequency profiles are 2.4 GHz (JEDEC), 3.6 GHz (XMP #1) and 4.0 GHz (XMP #2)

Given that this Intel CPU has Turbo Boost Technology, which claims

Intel® Turbo Boost Technology dynamically increases the processor's frequency as needed by taking advantage of thermal and power headroom to give you a burst of speed when you need it, and increased energy efficiency when you don’t.

as well as Dynamic Memory Boost, which claims

Intel® Dynamic Memory Boost simplifies system memory overclocking for the PC enthusiast, gamer or content creator. By leveraging the existing eXtended Memory Profile specification (XMP) for both DDR4 and DDR5 modules and 12th Gen Intel® Core™ desktop processors, Intel Dynamic Memory Boost automatically configures your system for enhanced memory performance on demand.

Now I am wondering, does the following build make sense? At which frequency will the CPU be running when idle? Is it the 2.9 GHz, which is CPU base, or 3.6 GHz which is the next "notch" for the RAM or something in between?

Thanks in advance!

 

[JohnBonhamsGhost]

At which frequency will the CPU be running when idle?

with C-States enabled and Windows Power Plan set properly your CPU will down-clock to 800MHz when idle.
when necessary it will boost up to it's 4.9GHz.

your memory speeds has nothing to do with your default CPU core speeds.

Just curious if anyone has some comments for or against combining the following

no

 

[uWebb429]

At which frequency will the CPU be running when idle?

If you are using the Windows High Performance power plan, Intel CPUs will run full turbo boost which means they will run as fast as possible. If you do not want a fast CPU when idle, you can use the Windows Balanced power plan which allows the CPU to slow down when it has nothing to do.

Everyone assumes that a fast CPU when idle is bad but if you enable the low power C states, it makes hardly any difference. Intel CPUs save power and run cool when idle cores are allowed to enter the low power C7 state. In this state, cores are disconnected from the internal clock so they are running at 0 MHz and the voltage is at 0 V. The belief that "we must run the CPU slow" has become pointless.

Here are 10 cores pegged at 5000 MHz with the CPU idle. Power consumption and CPU core temperatures are extremely low because the individual cores are averaging 99% of their time in the low power C7 state.

Dynamic Memory Boost

This sounds like a new name for XMP from the Intel marketing department. Run your memory at whatever speed and whatever timings it is happy to run at.

 

[ChipsFries]

Thanks a lot @uWebb429 for the detailed response and for the picture. This is a very new and interesting insight to me that running a CPU at full frequency does not necessarily imply it will get piping hot and consume a whole lot of power.

I think the new thing Intel is introducing here is hinted with automatically. I would assume in this scenario this means you do not have to go to BIOS and choose an XMP profile with higher/lower frequency yourself when you need or do not need it, but rather that the CPU itself does the speed up/down of RAM.

 

[JohnBonhamsGhost]

the new thing Intel is introducing here is hinted with automatically...
frequency profiles are 2.4 GHz (JEDEC), 3.6 GHz (XMP #1) and 4.0 GHz (XMP #2)

no, it states right in your post that XMP 1 is 3600MHz, XMP 2 is 4000MHz, and JEDEC default is 2400MHz.
without setting the XMP profile in the BIOS your memory will run at default 2400MHz.

Here are 10 cores pegged at 5000 MHz with the CPU idle. Power consumption and CPU core temperatures are extremely low because the individual cores are averaging 99% of their time in the low power C7 state.

whatever setup this user has is not how 99% of systems currently run.
with three Intel Core systems in this house alone i can verify that running full speeds at all times idle temperatures are ~10-20°C higher than with 5% minimal state enabled.

 

[uWebb429]

i can verify that running full speeds at all times idle temperatures are ~10-20°C higher than with 5% minimal state enabled.

Do you have the low power C7 state enabled in the bios? Some people set this to Auto in the bios without realizing that on some motherboards, Auto disables the C states. It is always best to check that the C states are working as intended. On my desktop computer and on my laptop, full speed when idle makes virtually no difference to power consumption or heat output or core temperatures.

@ChipsFries - I prefer setting the memory speed and timings to fixed values in the BIOS.

 

[ChipsFries]

no, it states right in your post that XMP 1 is 3600MHz, XMP 2 is 4000MHz, and JEDEC default is 2400MHz.
without setting the XMP profile in the BIOS your memory will run at default 2400MHz.

Can you please clarify this? I stated that there are 3 predefined profiles to choose (i.e. manually) from within BIOS, for this particular RAM stick. However, what Intel claims on this page is:

How Does Intel® Dynamic Memory Boost Work?

When enabled1 through BIOS, Intel Dynamic Memory Boost automatically programs and trains your system’s XMP base and performance memory profiles, and then seamlessly and intelligently transitions between both modes of operation in real time based on memory bandwidth demands.

I read this as "User enables this option once through BIOS and from then on, the CPU changes which profile will be active at what times, as it sees fit", but I could be just plain wrong.

@uWebb429 thanks for the advice. If the RAM and CPU frequencies are mostly unrelated, then I guess it makes sense to just set the RAM frequency once to some value and go with it.

 

[uWebb429]

RAM frequency

I think variable RAM speed has been a feature for a few years on Intel's mobile CPUs. Minimizing power consumption when your laptop is running on battery power makes sense. Saving a watt when plugged in is not that important. The price for electricity where I live is about 15 cents per kWh. It would take a couple of years with my computer idle to save a buck.

For a desktop computer, it makes sense to lock the memory to a fixed speed that it can run stable at.