We’re finally getting a clearer idea of what exactly a Steam Machine is, or at least what the insides of one could look like.

Developer and publisher Valve has revealed the specs for the first wave of Steam Machine prototypes. Steam Machines are Linux-based, customizable computers optimized for running Steam, Valve’s digital store and PC games service. Valve is sending the 300 prototype versions of the hardware to random, qualified Steam users.

“The prototype machine is a high-end, high-performance box, built out of off-the-shelf PC parts,” states Valve on its webpage announcing the specs. “It is also fully upgradable, allowing any user to swap out the GPU, hard drive, CPU, even the motherboard if you really want to. Apart from the custom enclosure, anyone can go and build exactly the same machine by shopping for components and assembling it themselves.”

Here are the specs for the 300 prototypes:

  • GPU: Some units with NVidia Titan, some GTX 780, some GTX 760, and some GTX 660
  • CPU: Some boxes with Intel : i7-4770, some i5-4570, and some i3
  • RAM: 16GB DDR3-1600 (CPU), 3GB DDR5 (GPU)
  • Storage: 1TB/8GB Hybrid SSHD
  • Power Supply: Internal 450w 80Plus Gold
  • Dimensions: Approx. 12-by-12.4-2.9 inches high

Those GTX video cards are important — those have the Kepler chips which can stream gameplay to Nvidia’s Shield. So this sheds light on the streaming component of a Steam Machine.

“Valve didn’t set out to create our own prototype hardware just for the sake of going it alone,” states Valve. “We wanted to accomplish some specific design goals that in the past others weren’t yet tackling. One of them was to combine high-end power with a living room-friendly form factor. Another was to help us test living room scenarios on a box that’s as open as possible.”

Valve has not yet released a picture of the prototype. Steam Machines will enter the market next year.