Valve today announced system specifications for its Steam Machine prototype, which the company will ship to 300 users this year as part of the limited hardware testing program.

GPU: some units with NVidia Titan, some GTX780, some GTX760, and some GTX660

some units with NVidia Titan, some GTX780, some GTX760, and some GTX660 CPU: some boxes with Intel : i7-4770, some i5-4570, and some i3

some boxes with Intel : i7-4770, some i5-4570, and some i3 RAM: 16GB DDR3-1600 (CPU), 3GB DDR5 (GPU)

16GB DDR3-1600 (CPU), 3GB DDR5 (GPU) Hard drive: 1TB/8GB Hybrid SSHD

1TB/8GB Hybrid SSHD Power Supply: Internal 450w 80Plus Gold

Internal 450w 80Plus Gold Hard Drive: 35GB HD space

35GB HD space Dimensionsapprox. 12 x 12.4 x 2.9 in high

In a statement on the Steam Community website, Valve described its prototype as "something special." It is built out of off-the-shelf PC parts and is fully upgradable, meaning users can swap out the GPU, hard drive, CPU, or the motherboard if they want to.

"To be clear, this design is not meant to serve the needs of all of the tens of millions of Steam users," Valve said about its prototype. "It may, however, be the kind of machine that a significant percentage of Steam users would actually want to purchase--those who want plenty of performance in a high-end living room package. Many others would opt for machines that have been more carefully designed to cost less, or to be tiny, or super quiet, and there will be Steam Machines that fit those descriptions.

Valve said it is not ready to share a picture of its prototype because "they're not finished enough." However, the company said it will post images of the device before units ship to testers this year. Valve also expects users to redesign the machine from a technical perspective and from an industrial design angle, changing the enclosure in new ways.

"So high-powered SteamOS living room machines are nice, and fun to play with, and will make many Steam customers happy. But there are a lot of other Steam customers who already have perfectly great gaming hardware at home in the form of a powerful PC," Valve said.

"The prototype we're talking about here is not meant to replace that. Many of those users would like to have a way to bridge the gap into the living room without giving up their existing hardware and without spending lots of money," Valve added. "We think that's a great goal, and we're working on ways to use our in-home streaming technology to accomplish it--we'll talk more about that in the future."

Valve's Steam Machine, as well as units made by a variety of companies, will be available beginning in 2014. Hardware specifications for those machines will differ, in many cases substantially, from Valve's system, the company said. Pricing has not been announced.

Valve ended its announcement today by telling fans to stay tuned for a "closer look" at the Steam Controller.