GoKawiilUnreleased AMD Ryzen 9 5900X3D prototype surfaces with 128MB L3 cache
An engineering sample of AMD's never-released Ryzen 9 5900X3D has appeared on the Chiphell forums, showing 128MB of L3 cache from 64MB of 3D V-Cache stacked on one of its two core complex dies. CPU-Z data also shows a clock speed near 4.65GHz, suggesting the chip could have nearly matched the retail Ryzen 9 5900X's boost clock. AMD had teased a 12-core '3D Chiplet Prototype' at Computex 2021 claiming up to 15% faster gaming performance than the standard 5900X.
GoKawiil's interpretation of the reporting above, not reported fact.
The leak confirms AMD experimented with multiple 3D V-Cache configurations for Zen 3, including versions with V-Cache on both CCDs reaching up to 192MB of L3 cache, as shown by Gamers Nexus at AMD's labs. This suggests AMD explored several high-cache gaming CPU designs before settling on the single Ryzen 7 5800X3D for retail, possibly to avoid cannibalizing other product lines or due to yield and cost constraints.
- A Ryzen 9 5900X3D engineering sample with 128MB L3 cache has surfaced on Chiphell forums.
- AMD teased a 12-core 3D V-Cache prototype at Computex 2021 but never released it commercially.
- Gamers Nexus found even more exotic variants with 192MB L3 cache, including a possible Ryzen 9 5950X3D.
AMD Ryzen 7 5800X3D — Since the 5900X3D never actually launched, the 5800X3D is the real-world AM4 chip that delivers that same 3D V-Cache gaming boost. It's a drop-in upgrade for existing AM4 motherboards, letting gamers get a huge frame-rate bump without a full platform overhaul.
See AMD Ryzen 7 5800X3D on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: tomshardware.com — Zhiye Liu, 2026-10-03
Published there as: “AMD’s secret Zen 3 gaming CPU had 128MB of game-boosting L3 cache but never saw the light of day”
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