Yes, my point was that the OS isn't currently doing it on its own, putting the onus on the driver developers -- which have limited information available to them

Yes, my point was that the OS isn't currently doing it on its own, putting the onus on the driver developers -- which have limited information available to them and are pretty much unable to make the right choice -- unless we're talking about highly customized embedded-type machines, or unless the user is willing to heavily participate in the process. It was just a simple example of something that could change for the better in terms of performance, but that probably won't because it's a significant amount of code churn with little $$$ benefit. I was honestly surprised that a core-balancing algorithm was added in Windows 7, but that was done at the last second (RC2) and by a very senior (while young) dev that had a lot of balls and respect. Sadly he was thanked by being promoted into management, as is usual with Microsoft.