Well it is not a hardware issue, just because the machine was performing better with windows 7 and 8.1 with the same hardware and OC. The OC is even a bit higher now.
Believe me, i build a X99 system with the i7 5820K @ 4,5GHz core & 4,1GHz uncore just for the sake of pumping as much power as possible towards the x264 encoder and actually take a look how far i can push the preset while maintaining playable fps ingame and streaming at 1080p 60fps.
The issue is almost impossible to catch, specially because everything else performs like it should and even better with Win10 than with 7 or 8.1. I have tested everything, compared the numbers from benchmarks like Cinebench R15, ASUS Realbench, Valley, Furmark and a shitload of other tools... Literally everything is working like it should.
By the way, the problem appeared after Microsoft pumped out some updates to connect the Xbone and added some functions. Remember what happened to game capture? This stuff was patched.
I believe it has something to do with that crap. It is disabled, but still... The Win10 that i use is also an Insider Preview build - so far i know we get early updates without overriding them with final versions for the normal customer if they work just fine.
I`m not complaining, just wondering what the heck is going on and why do i lose performance.
But so far this is a minor issue, i just have to adjust the settings and live with the higher CPU usage from OBS or maybe roll back to Windows 8.1 one day.
I dont even believe that if i just would bring the machine to you guys, that you will find the issue withhin a reasonable amount of time. Its sitting somewhere deep in the DX, no idea what Microsoft did there, but it is complicated.