Peek-a-Boo's "Special Technology" feature lets you customize how each process utilizes the CPU.
A little background: The MacOS uses what is called a "cooperative" multitasking model. That means that whenever you're running several processes, each one gives up the processor occasionally. At that time, it also says how soon it would like to use the processor again.
Sometimes a process doesn't make that request in as sophisticated a manner as it should. For example, there might be a word-processing program that demands as much of the CPU as possible, even when it's in the background and not doing anything. On the other hand, a database program might not request any CPU time, even though it really needs it.
These scenarios have always been visible in Peek-a-Boo: by watching the "CPU%" column, or creating a CPU history window, you can generally get a feel for some processes that are more CPU-hungry than others.
With the new features of Peek-a-Boo ST, you have the ability to adjust that. Each process may be set to one of four priorities: Normal, High, Medium, and Low.
By adjusting a process's priority to Normal, the "special technology" doesn't kick in, and the process behaves as it usually would without "special technology" at all. By setting it to High, that process will ask for all the CPU power available. By setting it to Medium, the "special technology" forces the process to be between High and Low priority. By setting it to Low, that process will ask for very little of the CPU power available.
Due to some of the awkward characteristics of the MacOS's cooperative multitasking model, these issues mostly arise, and the special technology mostly applies, when a process is in the background. When a process is in the foreground, the MacOS will give it plenty of CPU time, even if it doesn't request it!
Now, it's probably obvious that simply setting all processes' priority to High won't make your Mac run faster! There's only so much CPU power to divvy up between all the processes, and what Special Technology does is let you adjust how that CPU power is divvied up.
For example, suppose you're running an AppleScript that seems to be extra slow when a word processor is running. If that word processor is hogging the CPU, then you could use Special Technology to make the word processor low priority, leaving more CPU power available for the AppleScript. Or if your database needs to be more snappy if it's in the background, you could set it to high priority to ensure that any available CPU power gets allocated to it.
As you use Special Technology, you'll find that you occasionally need to manipulate a combination of processes' priorities. In other words, setting the "important" process to High priority may be only the first step; you may also need to set another process to Low priority. This is the main reason that I always turn on "CPU%" whenever I need to use Special Technology. That makes it very easy to see what needs to be manipulated, and how.
The Special Technology priorities are adjusted via the Processes menu. It is often convenient to use the popup menu (click and hold on a process, or option-click on a process) to adjust the Special Technology priorities.
To use Special Technology, you need to drag "PaB Special Technology" to your System Folder. The MacOS will automatically put it into the Extensions folder. You'll need to restart your computer before Special Technology takes effect.