Per Woofun AI, a technical dispute has intensified between research firms Citrini and SemiAnalysis concerning Nvidia's Rubin Ultra chip architecture. Citrini researcher Zephyr argued that Rubin Ultra HBM performance has regressed to the 12 Hi tier, citing high costs and low yield rates associated with hybrid bonding technology, while noting BESI's advantage through TSMC's adoption of this method for EIC and PIC integration.

In response, SemiAnalysis founder Dylan Patel presented evidence that clients utilizing SemiAnalysis models were notified as early as March that the Rubin Ultra 16 Hi configuration would be superseded by the 12 Hi version. Patel further contended that prior reports by Citrini researcher Jukan regarding Nvidia reducing memory configurations were taken out of context and sensationalized, actions which previously triggered declines in US and Korean memory stocks.