Microsoft is building fast, low-power neural networks with FPGAs. "Microsoft claims that new FPGA designs provide greatly improved processing speed over earlier versions while consuming a fraction of the power of GPUs. This type of work could represent a big shift in deep learning if it catches on, because for the past few years the field has been largely centered around GPUs as the computing architecture of choice."
"If there's a major caveat to Microsoft's efforts, it might have to do with performance. While Microsoft's research shows FPGAs consuming about one-tenth the power of high-end GPUs (25W compared with 235W), GPUs still process images at a much higher rate."