Intel i9-13900K and Clock Speeds

[Ray Proudfoot 9,217]

It was recommended by @Bob Scott I download HWInfo and I'm glad I did. After monitoring CPU temps I was relieved to see my cooling system is working well.

My question relates to the clock speed of the various cores. I had imagined all of the primary cores would run at the same speed - 5500. As you can see from the image below this is not the case. P4 and P5 run at 5800 compared to 5500 for the remaining 6.

With HT turned off I have a total of 24 VPs. The Efficiency Cores run at 4300 which seems fine but it's the two fastest cores I wany P3D v5.4 to take advantage of.

My JobScheduler entries in Prepar3D.cfg show 0, 2 and 4 are the best as determined by LM. But why wouldn't 4 and 5 be better as they run faster?

[Bob Scott 7,848]

That's normal--the 13900K runs two cores at a higher clock when there's no/low load, but if using the default intel scheduling they will downclock when a significant multi-core load is present.  I doubt you'll see those cores at 5.8 with P3D running, unless your builder manually configured the BIOS to lock those cores at those speeds.

The JobScheduler entries of 0/2/4 are just default settings--P3D does not do any sort of intelligent assignment based on differential core performance.

What I'd do is watch HWInfo with P3D running to determine if any of the cores are left to run faster than the others, and if so, first assign the main thread to that core and see if the core still runs faster.  I had to force that in the BIOS on mine after running many hours of overclock drills to determine which core was the most robust under load.

 

[Ray Proudfoot 9,217]

Bob, thanks for the explanation. It seems bizarre that two cores would run faster with little demand but as soon as demand increases they drop down to the level of others.

Monitoring the cores is a job for tomorrow. I shall watch it with interest. Whether I’m brave enough to dabble with BIOS settings I’ll leave for another day assuming it’s worth doing.

[Bob Scott 7,848]

51 minutes ago, Ray Proudfoot said:

Bob, thanks for the explanation. It seems bizarre that two cores would run faster with little demand but as soon as demand increases they drop down to the level of others.

Monitoring the cores is a job for tomorrow. I shall watch it with interest. Whether I’m brave enough to dabble with BIOS settings I’ll leave for another day assuming it’s worth doing.

In the BIOS "Tools" page there's a profiles page that allows you to save up to 10 BIOS configurations...if you save what you have before you touch anything, then you can always go back there and reload that saved BIOS config if tweaking gets you to a bad place.  You can also save those configs to a USB stick, so you can get back there if anything were ever to happen where you'd need to reset the BIOS to stock settings (e.g. a memory DIMM going south on you).

The boost of two selected cores is for light, 1-2 core workloads...maybe something like a spreadsheet in a business setting.  Not really much use for us.

[Ray Proudfoot 9,217]

19 minutes ago, Bob Scott said:

In the BIOS "Tools" page there's a profiles page that allows you to save up to 10 BIOS configurations

Thanks. I was looking for that in "My Favourites" as I thought that's where you could save different configs. The only significant changes I've made from when the PC was delivered are lowering water-cooling from "always on" to "Turbo" and turning off Hyperthreading.

I wish I had your confidence making these changes. I remain a reluctant tweaker when it comes to the BIOS.

[fairwinds47 0]

Bob, I see that you list a PFC yoke with Hall sensor retrofit in your system 1 inventory.  I have an old PFC Cirrus yoke from their PCATD system that I modified for USB by using an Arduino board.  My yoke uses sliding pots for the axis.  I am interested in converting those to Hall sensors.  Is yours a factory retrofit, or is it one you built on your own.  I would appreciate any recommendations you may have.  Thanks.  /Len

[Bob Scott 7,848]

5 hours ago, fairwinds47 said:

Bob, I see that you list a PFC yoke with Hall sensor retrofit in your system 1 inventory.  I have an old PFC Cirrus yoke from their PCATD system that I modified for USB by using an Arduino board.  My yoke uses sliding pots for the axis.  I am interested in converting those to Hall sensors.  Is yours a factory retrofit, or is it one you built on your own.  I would appreciate any recommendations you may have.  Thanks.  /Len

My PFC yoke is the floor-mounted version, which uses rotary transducers rather than the linear ones.  There used to be a couple of Honeywell Hall Effect sensor packages (a 90-deg and a 180-deg version) that were very close to drop-in replacements for the original rotary pots (same casing and shaft diameter).  Linear pots are a very different animal--I had to custom engineer a solution to replace the linear pots in my PFC throttle quad, which involved fabricating a set of brass piers that hold rare earth magnets, and brass mounts that hold Allegro HE chips attached to the old pot sliders that move between the magnets.  AFAIK, there still are no HE equivalents for those 100 KOhm sliders where they're used in the PFC hardware, which probably explains why PFC now uses HE transducers in its yokes, but still uses those pots in their throttle quad.

[fairwinds47 0]

On 12/4/2023 at 3:41 PM, Bob Scott said:

My PFC yoke is the floor-mounted version, which uses rotary transducers rather than the linear ones.  There used to be a couple of Honeywell Hall Effect sensor packages (a 90-deg and a 180-deg version) that were very close to drop-in replacements for the original rotary pots (same casing and shaft diameter).  Linear pots are a very different animal--I had to custom engineer a solution to replace the linear pots in my PFC throttle quad, which involved fabricating a set of brass piers that hold rare earth magnets, and brass mounts that hold Allegro HE chips attached to the old pot sliders that move between the magnets.  AFAIK, there still are no HE equivalents for those 100 KOhm sliders where they're used in the PFC hardware, which probably explains why PFC now uses HE transducers in its yokes, but still uses those pots in their throttle quad.

Thanks for the reply Bob.  I was hoping a simple drop-in solution such as yours would work.  Now I'll consider something like your throttle quad solution.  Or maybe some sort of rack and pinion to a rotary pot, if space provides.  Fun to consider the alternatives.   /Len