Disable Windows 7 CPU ‘Core Parking’
CPU Core Parking is a feature within Windows 7 known to cause stuttering within games on some systems. Core Parking disables (or “parks”) the cores on multi-core processors when the OS feels there is no need for them and enables them when needed — which can cause micro-stuttering.
By disabling this feature games can use all cores available by ‘un-parking’ all cores. If your game(s) suffer from micro-stuttering of any kind, than this registry tweak should help alleviate the problem. (this is also known as “Core Parking / Intelligent Timer Tick / Timer Coalescing”)
- Click on Start
- Type “regedit” in the “search programs and files” box
- From the registry window click “Edit” and select “Find“
- In the find field paste “0cc5b647-c1df-4637-891a-dec35c318583” (without quotes) and click “Find“
- Each key found will report two values labeled “ValueMax” and “ValueMin”
- Change “ValueMax” from “100” to “0“
- “ValueMin” should also read “0“
- Repeat by pressing “F3” to continue searching the rest of your registry for each key
(you should have anywhere from 2 to 3 entries throughout the registry)
- continue to change “ValueMax” to read “0″
By disabling this feature the operating system will load balance across the CPU cores without turning cores off/on when needed. Instead all cores will be enabled regardless of what the operating system tells the CPU and allow games and other applications to continue using all cores.
About Core Parking
Core parking is a new feature that dynamically selects a set of processors that should stay idle and not run any threads based on the current power policy and their recent utilization. The scheduler will attempt to honor this selection when it decides on which processors to run threads, allowing the parked cores to enter deep idle states where they consume very little power.
The affinity of a thread will always be honored. If a thread is affinitized to parked cores only, it will be scheduled to one of the parked cores. On a client machine, most threads do not explicitly set an affinity and therefore run with an affinity including all processors in the system, allowing for frequent use of core parking. On servers where applications are more often finely tuned, threads may be affinitized to specific processors, which can reduce the effectiveness of core parking.