Their first run of the prototype is a "high-end, high-performance" box with "off-the-shelf" PC components. Even though it's just a prototype, you can "swap out" anything inside, providing it fits.
Valve are keen to point out Steam Machines are "not meant to replace" people's already high-end PCs, as they don't want to mess with "perfectly great gaming" rigs.
"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," explained Valve's Greg Coomer.
"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. So for our own first prototype Steam Machine (the one we're shipping to 300 Steam users), 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. Apart from the custom enclosure, anyone can go and build exactly the same machine by shopping for components and assembling it themselves. And we expect that at least a few people will do just that. (We'll also share the source CAD files for our enclosure, in case people want to replicate it as well,)" he continued.
"And to be clear, this design is not meant to serve the needs of all of the tens of millions of Steam users. 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."
The Steam Machine prototype specifications:
◾GPU: 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
◾RAM: 16GB DDR3-1600 (CPU), 3GB GDDR5 (GPU)
◾Storage: 1TB/8GB Hybrid SSHD
◾Power Supply: Internal 450w 80Plus Gold
◾Dimensions: approx. 12 x 12.4 x 2.9 in high
Valve doesn’t want to threaten the already bulging raw power of people's gaming leviathans.
"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. The prototype we're talking about here is not meant to replace that," said Coomer.
"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. 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."
The proposed 'in-house streaming' of SteamOS means that you wouldn't require a powerhouse box in the living room for gaming as the Steam Machines would connect to your gaming PC, using its superior hardware to do all the hard work and then pipe in through to the living room to be blown up on the TV. Valve is tinkering with the tech now.
Check out theposted on Steam Community.