25/30% CPU usage can still mean CPU bound, 25% is 100% on one core, and game is mostsly single threaded. My previous config was an i7 4790K like you with my GTX1080 and it was hard to maintain 90fps, now I switched to Ryzen 2700X and it is much easier. There are two things your computer might be struggling with: - the first is GPU idle (it is the case for almost any GPU above 1070 kind of performance so with V56 it is your case too) if the GPU load isn't intensive enough it might even not try to reach higher GPU clock speeds, try to find wath settings taxes your GPU - the second is VR adds background application that are as important as the main game itself and in CPU power terms they become concurrent (vrcompositor & vrserver) so maybe you could try in the task manager to increase process priority of RRE64.exe to above normal as well as for vrcompositor & vrserver. This will tell the windows task scheduler that every requests from those processes must be served before other processes, otherwise it is FIFO and that can add very small delays that leads to inconsistant frame rates that will in the end trigger ASW (don't go to high or realtime there are diminishing returns for the first one and wrse perf with the later). If you can in steam VR activate the frame time graph in the head set to look to the smoothness and or spikes of the frame time as you test these changes. It will help to find when you tweak graphical settings wich hammers the GPU, wich hammers the CPU.