PSA: Beware of ‘Foreground boost’ cons
This is an except from our page here.
What about Foreground Boosting (NOT what ProBalance does)?
Foreground boosting is a common scheme used by some snake-oil software. Do not be fooled!
The foreground process is that which has the keyboard and mouse focus. This means there is only ever one foreground process at a time, per user session. Windows already applies foreground boosting by giving the foreground thread longer time slices. Further increasing the priority of the foreground process and/or the specific foreground thread is not only ineffective, but harmful. Remember, giving a process a higher priority does not mean it will run faster. It simply means if several processes are active at once, it will have a higher precedence. However, if any single process has too high a precedence over other processes, as foreground boosting would result in, complications can occur. This is partly because of the additional (and now very high) CPU priority ‘skew’ between the process and its dependencies.
Be very wary of any utility that claims to boost PC performance by increasing the priority of the foreground process. In some cases, the author of the program simply doesn’t understand the CPU scheduler and why this is a bad idea. In other cases, companies don’t care and are just trying to make a profit. In short, it is a very wrong solution and should be avoided at all costs.
Now, if you don’t care or believe your case is different, Process Lasso *does* have this feature, disabled by default (of course), so at least do it right with Process Lasso, but remember this warning!
UPDATE: Note the new Windows 10 Gaming Mode does *not* use foreground priority boosting, it instead relies on changes the CPU scheduler to give the foreground application longer time slices. This is an entirely different technology!