Disabling Speedstep as the solution to Windows 10 and Alder/Raptor Lake e-core related performance issues?

XoR_

[H]ard|Gawd
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Windows 11 always uses faster clocked cores first. This behavior I presume is unchanged from how Windows 10 does it.
Now e-cores have lower clocks than p-cores so how is it that Windows 10 has issues correctly scheduling game threads on p-cores?

Answer I came out with is: Windows 10 does not know e-cores will have lower clocks until thread is scheduled to run on any given core because all cores run at lowest available multiplier (something like 800MHz).
From point of view of Win10 all threads have the same performance so it will pick threads randomly at first and then pick ones which already are spun-up (have higher clock) and might as well schedule game thread on e-core and then even keep game thread there because from the point of view of system its the fastest core for as long as randomly something triggers p-core to make it have higher clock and then game thread might jump to p-core for as long as activity is constant to keep game thread on p-core.

I have not tested it yet but it seem to be completely impossible for Win10 to have issues with p-core/e-core design as long as Speedstep (otherwise also called Speed Shift) is disabled because in this case all threads have maximum clock speed at all times (unless thermal throttling...) and this alone provides prioritization.

This solution of disabling Speedstep course implies also disabling "Turbo" and manually doing overclocking so it might not be ideal for everyone...

If manual OC is something someone already is doing and the OC is not symmetrical (all p-cores have the same frequency configured - eg. when worse performing cores are downclocked a little to help with stability) then here is another the funny thing: even Windows 11 will have the same issue recognizing which is the fastest core if not all p-cores have the same maximum frequency.

For example this is my current configuration
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If I enable 'Speed Shift' in BIOS I will immediately get lower and inconsistent results in single threaded benchmarks like Cinebench.
In Task Manager I will see different cores being used for the duration of the test. Usually fastest core but not always.
On the other hand with all clocks being locked to their maximum values I will always see the fastest clocked core being used. Should I run second application in the background eg. SuperPi then which application will get 5.6GHz core and better results will entirely depend on which application has the focus and is treated as foreground application. This is exactly the kind of behavior I expect when running games !!!

Its of course less relevant for situation where all cores have configured the same maximum clock and in this case performance difference of having Speedstep on or off is much smaller.
It still exists though and Speedstep doesn't help with performance like at all. Same with core parking. These might be worth considering if there was significant power usage difference but especially with manual overclock with constant vcore the difference is so small (apparently doing nothing at eg. 5.5GHz uses the same amount of power as doing nothing at 0.8GHz, go figure...) it doesn't make any sense to use any of these power saving features at all.

Thought?

ps. Tested it with each p-core having different clock and only fastest cores have activity. E-cores on Win11 have activity only when I used more than 6 threads in Cinebench even if they had higher clock than p-cores. Activity on e-cores is also scheduled based on clock so in this case group with higher multiplier was used first.
ps2. Because of that it wouldn't work for power savings to configure few slower cores and expect background apps to run there. In the same manner Windows 10 would not schedule background applications on e-core.
Heck, with Speedstep disabled it would schedule processes less often on e-cores and only use them when p-cores are all used up...
... is there a way to disable Thread Director on Windows 11?
 
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