AI news Sep 15, 2026

This week · announced September 14

Inference-chip startup Positron AI raised $875 million at a $5 billion valuation, and its bet is 2TB of memory per accelerator.

According to DatacenterDynamics, the round was co-led by investors including NEA, Atreides Management, SemiAnalysis Capital and Netscape founder Jim Clark, and the money goes to taping out its second-generation chip, Asimov, and bringing its Titan inference system into volume production (DatacenterDynamics, 2026-09-14). The company says it targets memory-heavy AI workloads and claims 2TB of memory per Asimov accelerator and 8TB per Titan system, with bandwidth comparable to Nvidia's Rubin; tape-out is planned for October 2026 and volume production for the second half of 2027. Its first-generation chip, Atlas, is built by Intel in the US and is already shipping; the report does not say to whom. ⚠️ The memory specs, the "comparable to Nvidia Rubin" bandwidth and "three times the performance per watt of the H100" are all the company's own claims; the report gives no bandwidth figure and does not say what kind of memory it is. There is an ownership tie worth noting: the investment arm of SemiAnalysis, the semiconductor research firm, co-led the round, and its founder Dylan Patel joins the board. Our September 14 issue, main-line item 4, reported Nvidia's flagship dropping from 288GB to 192GB of memory per card, and the memory analysis it cited came from this same firm. ⇒ When you read its memory calls from now on, factor in that stake.