depending on your memory kit, M5gene is a great board
Samsung mems are the easiest way to go 2666C9-11 or 2800C9-12 on air is possible
[M] Corsair Dominator Platinum 16GB 2666C10 DDR3 Memory Kit Review
K I fixed my XMP not working issue on the M8E with 3201 bios.
If I flash with Sky Lake and allow the Kaby Lake compatible BIOS to initialise itself after the first boot with the same 6700K CPU, I always got these weird post code lockups. No matter what CPU or memory module was used. XMP was no longer working.
If I flash with a Kaby Lake CPU and let the BIOS initialise itself with the 7700K in the socket, the XMP seems to works fine with any CPU or module afterwards...
Go figure...
Such a powerful gpu needs more cpu speed... if the score doesn't scale with GPU clocks, it means your CPU is the bottleneck...
Which OS are you running ? Which driver ? Any LOD, D3D overrider, Which monitor (resolution and refresh rate)