I5 14400F Core count

[WBloodMoonW]

Hi there,

I got a new i5 14400f CPU which is suppose to include 10 cores 4 of which are E (efficiency) cores, despite that when I open task manager, CPU-Z or any other testing program. I can only see 6 cores which are the P (performance) cores.

I tried the following:

• Updating motherboard chipset.
• Updating BIOS.
• Tried installing MEI drivers. 

I would appreciate any help with how to activate the E cores on my PC as I am starting to think that i got scammed with this CPU.

P.S. what the h*ll Intel, what is this:
 

It is official Intel is unable to add two numbers together, and this is an official tool that Intel asks people to install before contacting support.

Kind regards, 
Noor Eldeen

[Eigenvektor]

You can usually disable E cores in BIOS. Double check this is not the case.

 

59 minutes ago, WBloodMoonW said:

It is official Intel is unable to add two numbers together, and this is an official tool that Intel asks people to install before contacting support.

The tool likely simply shows whatever information the CPU reports to it. So if the CPU is defective/misreporting, that could explain why it is showing nonsense.

[WBloodMoonW]

I just checked the BIOS, and I confirmed that all E cores are enabled and should be showing, I want to note that I changed a bunch of parts (basically the entire PC except for the storage and ram).

Could a new windows install solve this issue?

[Eigenvektor]

46 minutes ago, WBloodMoonW said:

Could a new windows install solve this issue?

Doubt it.

 

You could try booting from a Linux live-USB stick, see if it sees all cores. If that's the case, that would help confirm it's an issue on the OS side. If that also reports fewer cores than expected, it would point towards a hardware issue.

[leclod]

7 hours ago, WBloodMoonW said:

I tried the following:

• Updating motherboard chipset.
• Updating BIOS.
• Tried installing MEI drivers. 

So you updated the bios to the latest and it did reset ?

Which motherboard have you got ?

What does the Intel Processor Diagnostic Tool say ?

What does "Updating motherboard chipset" mean ?

What does "Tried installing MEI drivers" mean ?

Edited August 17, 2025 by leclod

[WBloodMoonW]

Yeah the bios was reset and I made sure that the E cores were all enabled.

What I meant by updating motherboard chipset was the drivers, there are drivers for the motherboard chipset.

I don't really know what MEI drivers were but when I looked it up it means "Management Engine Interface" its an Intel driver.

 

And thanks for the hint @Eigenvektor imma try checking the number of cores using a Linux USB, and report back what I find.

[unclewebb]

@WBloodMoonW

 

Open msconfig and make sure Number of processors is not checked. Save and reboot so Windows can find all of your cores. No need to reinstall Windows if you do this.

 

[WBloodMoonW]

Yeah that worked perfectly, thank you @unclewebb when I reloaded windows with that option unchecked the other threads and cores showed up as they suppose to, heck the CPU speed slowed down, and thank you @Eigenvektor after running in ubuntu, I checked and found all threads working