Valve has unveiled the first two “Steam Machine” gaming PCs for pre-order. It’s also taking orders for a dedicated controller and a streaming box for easier home set-up.

The two models come 18 months after Valve first announced its plans for a series of dedicated gaming machines designed to be closer alternatives to game consoles. The idea is to make them powerful enough for gaming but cheap enough that people will use them as dedicated gaming machines rather than spend money souping up their regular desktop PC.

Alienware’s model (pictured above) offers a 1080p output and a dedicated 2GB graphics card and will start at $449. The details of the Syber machine are a bit more vague: it starts at $499 and the makers are stressing the ease of upgrading it with standard off-the-shelf PC components.

It appears both machines will come with the standard Steam controller, which is also now available for pre-order on its own at $49.99. It combines the triggers, buttons and trackpads you’d expect in latest-generation console controllers with configurable elements designed to make it easier to play games that were made with keyboards and mice in mind.

For the same price you can also pre-order the Steam Link. That’s simply a plug-in box for your TV that lets you stream Steam games from a computer (whether Steam Machine or regular PC) in another room. The goal there seems to be to get more people into PC gaming even if their computer has a small screen and is in a setting that’s not too comfortable for relaxing rather than working.

With both the keyboard/mouse simulation and the streaming, the mere concept may not be enough for sales. Instead this really seems like a situation where it all comes down to how well things work in practice. One thing to watch out for in particular is whether the accessory performance varies significantly from game to game, which would undermine the entire console-like concept.