One of the feature implemented as part of performance improvement in ASP.NET vNext is – multi-core JIT compilation. This give a better performance boost specially after a cold site boot (e.g.. AppPool recycle, etc). This functionality is implemented in System.Runtime.ProfileOptimization.StartProfile method.
Thankfully, this feature is enabled by default. You don’t have to make your hands dirty to enable it. And, if you want to turn-off this feature, then do include the below code in your website’s web.config file.
2: <compilation profileGuidedOptimizations="None" />