Newer CPUs (Intel Core series and others) offer a variety of power-saving features. With Windows Vista and Windows 7, these features can be used to great effect, and some of them also improve performance of single-threaded applications. However, these features actually have a negative effect on multi-threaded applications that work near system time, such as Studio One and other DAWs.
These features include Speedstep (EIST), the C-States (C1e, C3, C6), Core Parking, and Turbo Boost. The following are descriptions of these features and their effects:
Speedstep and the C-States (C1e, C3, C6): allows disabling or throttling of individual CPUs. While this may not hurt performance directly, waking those CPUs to full power takes time, leading to processing peaks and crackles/drop-outs.
Core Parking: disables individual CPUs (normally the virtual hyper-threading ones) and is used for OS-based multi-core-scheduling. This also leads to delays on parking/unparking, causing crackles and drop-outs.
Turbo Boost: enables internal overclocking of individual cores/CPUs, while at the same time shutting down other cores (keeping temperatures safe). While this can raise performance of single-threaded applications by up to 10%, the switching causes delay, and therefore crackles/dropouts.
All of these delays can additionally hurt internal bus communication, causing, for instance, issues with the FireWire bus. So, if your FireStudio, or other FireWire interface, is not working correctly, even though you have a nice big Intel Core i7 processor, this might be the reason.
What is the solution?
So, how do you avoid all this trouble? As a PC-user, you could go into the BIOS and explicitly disable these features across the board. But, you might be putting your computer to other uses where these features actually help. So, we created an additional power profile (Vista/Win7 only) which you can switch to/from at any time, even while applications are running.
Download the 'audio-power-settings zip' file and follow these instructions:
Extract the zip file to the C:/ root directory.
Navigate to the 'addconfig.cmd' file, right click on it and select 'Run as Administrator'.
A pop-up window will very briefly appear, indicating the command is running. When this disappears, the new power profile should already be selected and in use. Check this under Control Panel/Hardware and Sound/Power Options.
What exactly does this profile do?
This 'Audio Processing' profile disables processor idle states, processor throttling, core parking and Turbo Boost. You can go to the Power Options and deselect this profile at any time, if you want to use your computer as a low power media-server, for instance. Then, before (or while) running Studio One, select the 'Audio Processing' profile, and all is well.
To see the results of this power profile in action, open the Task Manager and view Performance, switching back and forth from the Audio Processing profile and any other. If this power profile has any negative impact on your system, simply switch to another profile. There are no permanent changes made to your system with this profile.
[this tweak is not recommended for Windows 8 Systems!]