Solved 13900KF thread count with E-Cores and HT disabled

[shoober420]

I have a 13900KF CPU in my machine. When I played CS2, I got a lot of stuttering. I did some research to find its caused by the E-Cores. I came across numerous threads that mention the E-Cores effect other games negatively as well. My conclusion was to completely disable E-Cores in BIOS (no longer an Intel fanboy after this).

After installing the new F15 BIOS for my Aorus Master Z790 motherboard to remedy the voltage issues these chips are having (another reason im not an Intel fanboy anymore), I decided to hold off overclocking this CPU for now.

When updating my scripts for Windows, one of my network tweak scripts has a tweak that requires adjusting thread count based on CPU. According to the spec sheet, the 13900KF has 32 threads.

Intel® Core™ i9-13900KF Processor (36M Cache, up to 5.80 GHz) - Product Specifications | Intel

Intel® Core™ i9-13900KF Processor (36M Cache, up to 5.80 GHz) quick reference with specifications, features, and technologies.

ark.intel.com

I confirmed this using "msinfo32", and it saying "32 logical processors", which im assuming means threads. This is at default BIOS options and E-Cores enabled. I just went and tweaked my BIOS settings to what I normally use, and disabled the E-Cores, to discover that now msinfo32 reads "8 logical processors".

So im guessing that to get all 32 threads for the processor to function, E-Cores must be enabled. For reasons mentioned previously, Im keeping E-Cores disabled. My soul is crushed with Intels design philosophy. IMO, if a core isnt going to be a full performance P-Core, then dont have the core at all, but thats a different discussion.

What i want to confirm and clarify, is that with all 8 P-Cores enabled, and all E-Cores disabled, will there be only 1 thread per core? Meaning, with all E-Cores disabled, is the 13900KF an 8 core / 8 threads processor?

 

[neemobeer]

No, P cores are hyper threaded meaning they all have 2 threads per core. E cores are single threaded.
8 P Cores = 16 Threads

 

[shoober420]

No, P cores are hyper threaded meaning they all have 2 threads per core. E cores are single threaded.
8 P Cores = 16 Threads

I have hyper-threading disabled in BIOS as well, as Ive always known for hyper-threading to only benefit servers and video editing workstations, and negatively effect gaming performance. If I have hyper-threading disabled, does that mean I have 8 instead of 16 threads?

Here is a full list of tweaked settings in my BIOS.

game-configs/bios.txt at main · shoober420/game-configs

Video game configuration files. Contribute to shoober420/game-configs development by creating an account on GitHub.

github.com

 

[shoober420]

Well I just googled and it appears this is the case. Instead if my P-Cores having two threads per core, its now one per core. I also came across this article.

Disabling SMT or Hyper-Threading for Better Latency - XBitLabs

When it comes to game performance it is important to understand that although of great significance FPS is not the only measure you should be looking at. Another measurement that is as important as FPS (in my subjective opinion) is latency or how fast your PC executes inputs from your...

www.xbitlabs.com

I was happy to read it didnt lower his FPS when going from 16 threads to 8 threads. This makes sense, as most games dont benefit from more than 8 threads anyway. I guess this has always been Intels philosophy, being most games dont take advantage of more than 8 cores and 8 threads. This doesnt appear to be the case for CS2 though, as AMD crushes Intel in CS2.

 

[abactuon]

But have you run any programs to check how the CPU cores are loading ?
Source 2 is quite modern engine and ge can be so completely bad.

 

[shoober420]

But have you run any programs to check how the CPU cores are loading ?
Source 2 is quite modern engine and ge can be so completely bad.

Well the reason being is that various engines, not just Source 2, arent optimized to prioritze the P-Cores over the E-Cores, and will offload important computation to the E-Cores, which are meant for less intensive computing tasks.

One can argue that this is simply bad CPU design, and every single core should be treated equally so that game engines dont have to be specifically optimized for E-Cores. Sounds like a headache for game engine programmers. I would rather the CPU die have 2 additional P-Cores than 6 E-Cores taking up the die space on it.

 

[abactuon]

I haven't tested how it works

Power Setting GUID: 93b8b6dc-0698-4d1c-9ee4-0644e900c85d (Heterogeneous thread scheduling policy)

GUID Alias: SCHEDPOLICY
Possible Setting Index: 000
Possible Setting Friendly Name: All processors
Possible Setting Index: 001
Possible Setting Friendly Name: Performant processors
Possible Setting Index: 002
Possible Setting Friendly Name: Prefer performant processors
Possible Setting Index: 003
Possible Setting Friendly Name: Efficient processors
Possible Setting Index: 004
Possible Setting Friendly Name: Prefer efficient processors
Possible Setting Index: 005
Possible Setting Friendly Name: Automatic
Current AC Power Setting Index: 0x00000005
Current DC Power Setting Index: 0x00000005

Setting:
Heterogeneous thread scheduling policy

Description:
Specify what thread scheduling policy to use on heterogeneous systems.

Subgroup:
Processor power management

Possible values (index - hexadecimal or string value - friendly name - descr):
0 - 00000000 - All processors - Schedule to any available processor.
1 - 00000001 - Performant processors - Schedule exclusively to more performant processors.
2 - 00000002 - Prefer performant processors - Schedule to more performant processors when possible.
3 - 00000003 - Efficient processors - Schedule exclusively to more efficient processors.
4 - 00000004 - Prefer efficient processors - Schedule to more efficient processors when possible.
5 - 00000005 - Automatic - Let the system choose an appropriate policy.

 

[shoober420]

I do use the "Ultimate Performance" power plan on Windows 11, which is what every gamer should use. Although thats cool that Windows has some power plan options to adjust the P-Core and E-Core usage, I would rather simply disable the E-Cores in BIOS to guarantee the system doesnt offload to them and not rely on software policies to do so, as theres less chance for error.