yakamaster :
Then there is no performance enhancement or what so ever?
Nope.
Cores are unparked by default. Parking is something that an operating system can do to put a core to sleep when there's not enough work to do to justify keeping it powered up.
When threads (and/or processes depending on the operating system's model) become ready for execution the operating system has a decision to make. If one or more cores are parked it can wake them up and load the thread/process onto the logical processor representing that core. However, this causes the microprocessor to consume more power. Alternatively it can keep the cores parked and simply throw the thread/process onto the ready queue. This causes the thread/process to wait longer in the queue than it would normally, but avoids waking the core.
I'm not certain what mathematical model Windows uses by default to determine when to unpark cores, but it's most likely some sort of moving average of utilization or queuing delay. In fact, it may be faster to simply wait in the queue and run on a logical processor that's already unparked rather than wait for one that is parked to be awoken. Once the utilization level rises above a certain threshold (where utilization is the fraction of time spent running processes other than the idle process) or the mean time spent in the ready queue exceeds a certain value it would make sense to wake a core up. Various power settings most likely just move these setpoints around. It is possible to configure the operating system to never park cores at all but it already does a very good job of handling this on its own.
Facebook
Twitter
Instagram