When Valve announced their Steam Machines BETA program and listed the specifications for the BETA units the GPUs that were listed included the NVIDIA GTX Titan, GTX 780, GTX 760 and GTX 660. So it looked like official Steam Machines would be an all NVIDIA affair. In a recent interview Valve’s Doug Lombardi said that this is not true.
“Although the graphics hardware that we’ve selected for the first wave of prototypes is a variety of Nvidia cards, that is not an indication that Steam Machines are Nvidia-only,” he said. “ In 2014, there will be Steam Machines commercially available with graphics hardware made by AMD, Nvidia, and Intel. Valve has worked closely together with all three of these companies on optimizing their hardware for SteamOS, and will continue to do so into the foreseeable future.”
So it looks like Valve’s Steam Machines will feature different GPU options. Steam Machines are expected to be released in early 2014.