Valve will be giving out prototypes of its "Steam Box" PC hardware to customers to "gauge their reactions" in the coming months, co-founder Gabe Newell tells the BBC, adding that certain engineering decisions are still being finalized.

Newell says Valve is working with partners to "nail down how fast we can make" the hardware, explaining that balancing power with noise and heat output is part of the ongoing challenge. Valve already has one announced partner developing Steam-optimized hardware, mini PC manufacturer Xi3.

According to Newell, the Steam Box's controller is also still being finalized, with Valve continuing to explore biometric sensors for additional inputs.

Valve has long discussed using biometrics to tailor game experiences for players, explaining to the BBC that in a horror action game like Left 4 Dead, directly measuring "how aroused the player is" based on heart rate can offer players "a new experience each time they play."

The BBC's report intimates that it's Valve's controller that is holding up its hardware efforts.

Newell detailed some of Valve's plans for its long-rumored Steam Box hardware at this year's CES, telling The Verge, "We'll come out with our own and we'll sell it to consumers by ourselves."