So, Windows added a little feature a while back to help save power.\u00a0 Unfortunately, it can have serious side effects for gaming and other high-performance computing.<\/p>\n
Windows 7 \/ Server 2008\u00a0 machines running on multi-core CPU’s have an obscure feature enabled by default called CPU core parking. While usually benign – some people have experienced serious issues that seem completely unrelated to this feature.\u00a0 The symptoms are a decrease in performance with unstable and jittery in-game FPS, or noticeably laggy\/jittery and unresponsive game play.\u00a0 All this despite a high-end graphics card and CPU that should be more than capable of running the game. People have often seen this problem or described it as micro-stuttering – random fractional frame pauses that are hard to pin down precisely but are definitely noticeable and detrimental to game play.<\/p>\n
Core parking comes in at this point.\u00a0 Modern multi-threaded games often can leave a core idle for micro-portions of the frame after it has completed it’s processing and other cores are still finishing their work up.\u00a0 Windows sees this idling, and decides to put the idle core in low-power mode.\u00a0 Normally, threads go idle for long periods of time (often hundreds to thousands of milliseconds), so putting them to sleep is fine and can save power.\u00a0 But in a game, the core goes idle only to be woken up only microseconds later for the next frame.\u00a0 Unfortunately, parking and unparking has a time cost associated with the operation of a couple of micro\/milliseconds – which when rendering 60+fps – actually creates noticeable tiny ‘hitches’.\u00a0 It often appears randomly because it requires just the right set of conditions to cause the parking\/wakeup to be visible.<\/p>\n
So, what to do?\u00a0 You can actually disable this ‘feature’ – which on a gaming rig – is probably the right action since it’s unlikely that power saving is your highest concern.\u00a0 How do you do it?\u00a0 Just like this:<\/p>\n