Leaked docs hint Google may use SiFive RISC-V cores in next-gen TPUs
Would put those AI accelerators out of Arm's reach, at least
Opinion After a difficult 2023, things may be looking up for RISC-V chip designer SiFive, which expects AI to drive strong revenue growth in 2024.
According to documents obtained by Bloomberg this week, the Silicon Valley upstart's rebound will be driven by a second-gen processor designed for AI servers, or so the biz hopes.
Though the business news wire didn't make clear which chip family we're specifically talking about here, "second-gen" would suggest – and it's not been confirmed – an expanded partnership to provide SiFive processor cores for Google's tensor processing units (TPUs).
Those Google AI accelerators, now in their fifth generation, were initially designed to accelerate Google's internal machine learning workloads. More recently, the search giant has started making them available to the public to run their own AI training and inference jobs.
And as we've previously reported, at least some of these accelerators are already using SiFive's Intelligence X280 cores as a coprocessor to manage the device and feed Google's matrix multiplication units (MXU) with numbers to crunch.
Beyond the fact Google used the cores, we don't know whether they were ever deployed at scale or if they were just implemented as an experiment. Google may be waiting for a second-generation to more widely deploy.
What we do know is last October, SiFive announced the X280's successor, the X390, alongside its performance-optimized P870 cores. That X390 could be the basis of the aforementioned second-gen part.
The X390 is a 64-bit RISC-V processor core specifically designed to accelerate large vector instructions common in AI/ML workloads. It offers an instruction set along the same lines as Intel's AVX512. More importantly, the core features SiFive's Vector Coprocessor Interface Extension, which would allow it to be integrated with Google's MXUs.
The Register has reached out to both Google and SiFive for comment; we'll let you know if we hear anything back.
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In any case, the documents would seem to suggest a sizable uptick in revenues for SiFive from licenses and royalties.
According to Bloomberg, SiFive now projects sales of at least $241 million in 2024. This marks a sizable turn around for the biz which in 2023 netted just $38.2 million in revenues resulting in a $113 million operating loss for the year.
Despite support from major chipmakers, including Intel and Qualcomm, SiFive has faced headwinds in its attempts to challenge rival Arm. Last October, the RISC-V CPU designer laid off 20 percent of its staff amid a company-wide restructuring.
Meanwhile, on the national front, the RISC-V world has faced calls by US lawmakers to restrict the export of RV designs to China. ®