Microsoft on Monday released a white paper explaining a current effort to run convolutional neural networks — the deep learning technique responsible for record-setting computer vision algorithms — on FPGAs rather than GPUs.
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. Nvidia’s Tesla K40 GPU can do between 500 and 824 images per second on one popular benchmark dataset, the white paper claims, while Microsoft predicts its preferred FPGA chip — the Altera Arria 10 — will be able to process about 233 images per second on the same dataset.
However, the paper’s authors note that performance per processor is relative because a multi-FPGA cluster could match a single GPU while still consuming much less power: “In the future, we anticipate further significant gains when mapping our design to newer FPGAs . . . and when combining a large number of FPGAs together to parallelize both evaluation and training.”
In a Microsoft Research blog post, processor architect Doug Burger wrote, “We expect great performance and efficiency gains from scaling our [convolutional neural network] engine to Arria 10, conservatively estimated at a throughput increase of 70% with comparable energy used.”
This is not Microsoft’s first rodeo when it comes deploying FPGAs within its data centers, and in fact is a corollary of an earlier project. Last summer, the company detailed a research project called Catapult in which it was able to improve the speed and performance of Bing’s search-ranking algorithms by adding FPGA co-processors to each server in a rack. The company intends to port production Bing workloads onto the Catapult architecture later this year.
There have also been other attempts to port deep learning algorithms onto FPGAs, including one by State University of New York at Stony Brook professors and another by Chinese search giant Baidu. Ironically, Baidu Chief Scientist, and deep learning expert, Andrew Ng is big proponent of GPUs, and the company claims a massive GPU-based deep learning system as well as a GPU-based supercomputer designed for computer vision. But this needn’t be and either/or situation: companies could still use GPUs to maximize performance while training their models, and then port them to FPGAs for production workloads.
Expect to hear more about the future of deep learning architectures and applications at Gigaom’s Structure Data conference March 18 and 19 in New York, which features experts from Facebook, Microsoft and elsewhere. Our Structure Intelligence conference, September 22-23 in San Francisco, will dive even deeper into deep learnings, as well as the broader field of artificial intelligence algorithms and applications.
