{"rewrite":{"id":"r_4a03a30c3469baceb4e5f63a","clusterId":"c_709cb7e535f5402a22c6cddc","slug":"nvidia-cancels-rubin-ultra-development-after-cowos-l-warping-failures","model":"deepseek-v4-flash:free","headline":"NVIDIA Cancels Rubin Ultra Development After CoWoS-L Warping Failures","summary":"NVIDIA canceled original Rubin Ultra development after CoWoS-L interposer warping made prototypes non-functional. The 180-layer CoWoS-L warped in multiple directions, causing dies and wiring to peel. NVIDIA shifted to calling a different configuration Rubin Ultra and introduced a stopgap NVL576 rack solution using eight NVL72 (V2) units.","whyItMatters":"The cancellation explains Rubin Ultra's disappearance from NVIDIA's roadmap and the sudden NVL576 stopgap, signaling a manufacturing limit in TSMC's CoWoS-L that forced a redesign.","webCardHtml":"\u003cp\u003eRubin Ultra was to pair four GPU dies with eight HBM4E stacks on a 9.5-reticle CoWoS-L interposer planned for 2027. The 180-layer wiring layer warped in multiple directions when manufactured, peeling dies and wiring and leaving the interposer non-functional. The first prototype failed in early 2026, and a second prototype also failed, prompting the cancellation.\u003c/p\u003e\u003cp\u003eNVIDIA and TSMC began redesigning after the first failure, but uncertainty persisted through March, which is why Rubin Ultra stayed on the roadmap at GTC. The current plan reuses the Rubin Ultra name for a different configuration. The NVL576 rack solution announced at GTC, built from eight NVL72 (V2) units on the Oberon Rack, appears to be a stopgap to reach 576 GPUs without the original Rubin Ultra.\u003c/p\u003e","blueskyPost":"NVIDIA canceled original Rubin Ultra after CoWoS-L warping made prototypes non-functional. NVL576 stopgap uses eight NVL72 (V2) racks. Rubin Ultra name now applies to a different config.","twitterPost":"NVIDIA canceled original Rubin Ultra development after CoWoS-L interposer warping caused failures. NVL576 stopgap uses eight NVL72 (V2) units. Rubin Ultra name now applies to a different config.","threadsPost":null,"newsletterBlurb":"NVIDIA canceled original Rubin Ultra development after CoWoS-L interposer warping caused prototypes to fail. The NVL576 rack solution announced at GTC appears to be a stopgap using eight NVL72 (V2) units, and the Rubin Ultra name now applies to a different configuration.","attributionJson":"[{\"source\":\"ASCII.jp\",\"url\":\"https://ascii.jp/elem/000/004/426/4426042/?rss\",\"title\":\"The Truth Behind the Cancellation of NVIDIA Rubin Ultra Development: The 180-Layer CoWoS-L Warping Issue and the Hasty NVL576 Rack Solution\"}]","lintFlagsJson":null,"lintHits":0,"costUsd":0,"inputTokens":4734,"outputTokens":602,"status":"published","repairAttempts":0,"nextRepairAt":null,"factsAttemptedAt":1786334345,"createdAt":"2026-08-10T03:55:25.000Z","publishedAt":"2026-08-10T03:56:44.000Z","updatedAt":"2026-08-10T03:55:25.000Z"},"cluster":{"id":"c_709cb7e535f5402a22c6cddc","canonicalTitle":"NVIDIA Rubin Ultra開発中止の真相！ 180層CoWoS-Lの歪曲トラブルと、急造ラックNVL576に透ける苦肉の策","representativeArticleId":"a_60bd07e6ef68408ff98922d8","sourceCount":1,"writtenSourceCount":1,"writeAttempts":0,"isSolo":true,"entitiesJson":"{\"anime_titles\":[],\"manga_titles\":[],\"work_titles\":[\"NVIDIA Rubin Ultra\"],\"studios\":[\"NVIDIA\"],\"people\":[\"Benjamin G. Lee\"],\"type\":\"news\",\"domain\":\"other\",\"is_roundup\":false}","contentType":"news","status":"published","firstSeenAt":"2026-08-10T03:00:00.000Z","lastSeenAt":"2026-08-10T03:00:00.000Z","updatedAt":"2026-08-10T03:56:45.000Z"},"attribution":[{"source":"ASCII.jp","url":"https://ascii.jp/elem/000/004/426/4426042/?rss","title":"NVIDIA Rubin Ultra開発中止の真相！ 180層CoWoS-Lの歪曲トラブルと、急造ラックNVL576に透ける苦肉の策"}],"entities":{"anime_titles":[],"manga_titles":[],"work_titles":["NVIDIA Rubin Ultra"],"studios":["NVIDIA"],"people":["Benjamin G. Lee"],"type":"news","domain":"other","is_roundup":false},"keyFacts":null}