The first entertainment and gaming consoles running Valve's SteamOS will be powered by Intel central processors and sport Nvidia graphics chips, the video game developer and distributor announced on Friday.

Valve will be shipping 300 prototype units to Steam beta testers who sign up for the special program before Oct. 25. Those systems will come equipped with either an Intel Core i7-4770, Core i5-4570, or an unspecified Core i3, the company said in a blog post.

The prototype "Steam Machines" will use one of the following high-performance Nvidia GPUs: a Titan, GeForce GTX780, GTX760, or GTX660. The units will come with 16GB of DDR3-1600 memory for the CPU and 3GB of GDDR5 memory for the GPU, while internal storage will come in the form of a hybrid hard disk-solid state drive with 1TB capacity in the HDD portion and 8GB in the SSD.

The dimensions of the first SteamOS consoles, which Valve is billing as a "PC for the living room," are 12 by 12.4 by 2.9 inches, the company said.

"Valve didn't set out to create our own prototype hardware just for the sake of going it alone—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," the company said in its blog post.

"So for our own first prototype Steam Machine ... we've chosen to build something special. The prototype machine is a high-end, high-performance box, built out of off-the-shelf PC parts. It is also fully upgradable, allowing any user to swap out the GPU, hard drive, CPU, even the motherboard if you really want to."

Valve is also working with third-party computer makers such as Xi3 on SteamOS-ready systems. Xi3 recently announced that its $999 Piston game console, dubbed the first unofficial "Steam Box" when it was unveiled in March, will be made generally available on Nov. 29, or Black Friday.

PC Magazine