Looking at the target system specifications for the Windows Holographic First Run, which is present in the new Windows 10 Insider builds, I assume Microsoft isn't really targeting hardcore gaming applications but is instead focusing on content creation, casual gaming and some other tasks.
In the latest test builds of Windows 10, Microsoft is now including a "Windows Holographic First Run" application that tests a machine to ensure it’s compatible. I’ve tested a variety of machines, and it appears that Microsoft’s minimum requirements are pretty basic:More detail at The Verge.
4GB of RAM USB 3.0 port A graphics card with DirectX 12 support 4 CPU cores, including dual-core processors with hyperthreading