In effort of trying to get at least some performance back against PS4 that took commanding lead with 50% stronger GPU and more dev-friendly memory system, Xbox One team at MS unlocked 7th CPU core [shared between game and some OS services] and added a slight overclocking, which has over the last year provided some wins against PS4 in heavy CPU-processing scenarios. Now it looks like Sony has updated its SDK [as quietly as always] and enabled their developers to also access 7th CPU core. Proof comes from the changelog of the recent update of FMOD, a popular audio gaming middleware.
Code:Firelight Technologies FMOD Studio API Detailed Revision History 17/11/15 1.07.03 - Studio API patch release (build 69975) Features: LowLevel API - When using System::recordStart the provided FMOD::Sound can now be any channel count, up/down mixing will be performed as necessary. LowLevel API - Improved performance of convolution reverb effect when wet is 0 or input goes idle. LowLevel API - PS4 - Added FMOD_THREAD_CORE6 to allow access to the newly unlocked 7th core.
[found by Mabru from B3D]
While MS was very loud with promotion on their SKD updates [they needed a good word mouth this gen], Sony is usually very quiet on their releases, even substantial ones [PSP CPU overclocking abbility, numerous PSP&Vita&PS3 shrinking of OS memory footprint,etc]. On the same page you can find that FMOD got support for 7th Xbone core in January of 2015.
/compile my conciousness in single-threaded DX11 code if old