I know that the High Performance power plan does not only affect the CPU frequency, but also SSD/NVMe power management and many other things that can increase the performance.
Would you agree to make a test ?
With the defaulted power plans :
Set the power plan on Balanced and set the Minimum Processor State to 100% so the CPU clock is always at its maximum.
Open whatever project in Cubase or run any benchmark program.
Now set the power plan on High Performance, and compare Cubase performance or benchmark scores.
Do you see any noticeable difference between the two power plans ?
If you do, then I’m really impressed.
If we follow the same logic, the Ultimate Performance power plan is supposed to give even better performances than the High Performance one. But no one would actually see the difference in a real world setup.
No, disabling C-States doesn’t make the CPU run at full power all the time.
It only disables the CPU power saving features.
Basically, C-States are only really useful when the computer goes into sleep, when the screen turns off, or when you let the computer idle and there is almost no load.
Of course C-States also work when you actually use the computer under certain types of load, but then this is more of a passive thing to help save power even more.
The C-States won’t be as deep as in the situations above.
A core can enter and exit soft C-States many times per second, but doing so will cause the core to be unavailable for the time it takes to “wake up” when it gets told to work. This feature indeed steals some CPU cycles and can lead to lower performance.
Since Cubase usually has a relatively low CPU usage (I mean even with a 50 tracks project, the load is very far from a constant 100% usage like 3D renders), disabling C-States can for sure help, but the improvement will be very slight, if not absent in most cases.
Disabling C-States isn’t a magical performance solver.
The ability for the CPU clock to change is not related to the C-States, but to EIST (Enhanced Intel SpeedStep Technology) and the more recent Speed Shift.
For the CPU frequency to be able to move, either of EIST or Speed Shift may be enabled.
For the best reactiveness concerning the speed at which the CPU clock can change, I highly recommend to enable both EIST and Speed Shift.
Speed Shift is the most important setting you can actually enable. The CPU Clock will react extremely fast to any load, and will not cause any performance issue.
Speed Shift is extremely well implemented into Cubase, if not the best implementation in any software I’ve used, so there is absolutely no reason not to allow dynamic clock with Cubase.
It is possible to get the CPU to react to the load, even with the High Performance power plan.
The adaptive clock in relation to the load is governed by a hidden Power Plan setting called “Processor energy performance preference policy”, and the usual Min/Max Processor State settings, which simply set the clock limits.
This hidden setting is the Speed Shift fine-tune, and acts like a soft knee threshold where the CPU clock can change depending on the load.
When High Performance power plan is selected, this setting is set to 0 by default, and that is why the CPU will work at max speed, even when there is no load.
To make it visible in Power Plan settings, you must go into the registry, search for this entry and change the Attributes value to 2 :
Now it is visible, you can go into your High Performance power plan settings, and change the value to somewhere between 30 and 40.
It depends on the number of background tasks you have during idle, so experiment accordingly, and use a monitoring graph when you do so, for example Afterburner/RTSS.
However, don’t forget to set the Minimum Processor State to 0%, don’t keep it at 100% or the clock won’t be able to move.
With only the default background programs running, and without touching your mouse (idle), you should aim for a flat line on minimum CPU clock.
It may do some spikes but that’s not a problem, you even should allow it to make some spikes from time to time during idle, for example when Windows fetches updates and does its things, and most importantly when you move the cursor over the desktop.
The latter would confirm that the system will be as responsive as possible to any load, and at the same time reducing power consumption when there isn’t.