AMD 9950X3D2 CPU Rumor: Why Dual V-Cache Doesn't Make Sense

The 9950X3D2 Rumor

• 💡 The internet is buzzing about a rumored AMD 9950X3D2 CPU, which is speculated to feature dual 3D V-Cache CCDs.
• ⚠️ However, the speaker believes this rumor is unlikely to be true due to significant tradeoffs.

AMD's Chiplet Design Philosophy

• 🚀 AMD has utilized a chiplet design since 2016, where multiple smaller CPU cores connect via an Infinity Fabric.
• 🧩 Early chiplet designs faced latency issues between CCDs, a challenge Intel initially criticized but now employs with its tiled architecture.
• 📈 AMD's Ryzen architecture has matured significantly, building brand trust and becoming dominant in the CPU market.

Asymmetrical vs. Symmetrical Designs

• 🧠 Current X3D CPUs like the 9950X3D use an asymmetrical design with one CCD optimized for 3D V-Cache and another for higher frequency.
• ⚡ Zen 5 architecture improvements allow for higher frequencies on the V-Cache CCD by placing the core directly on the substrate, improving heat transfer.
• ⚠️ The speaker argues that a symmetrical dual V-Cache design (9950X3D2) would reintroduce cross-CCD latency, negating the benefits of having dedicated gaming and frequency CCDs.

Why Dual V-Cache CCDs Are Problematic

• 🎯 For gaming, keeping processes on a single CCD is crucial to eliminate latency; a dual CCD setup, even with improved interconnects, introduces potential delays.
• 📉 Even with a hypothetical symmetrical dual CCD design, a single, more powerful 8-core CCD with 3D V-Cache might still outperform a dual-CCD setup due to latency.
• 💰 The high production cost of 3D V-Cache makes doubling it on a single CPU economically questionable.

Alternative AMD Innovations

• 💡 The speaker suggests that process improvements to increase core clocks or a single, larger 16-core 32-thread CCD with 3D V-Cache would be more impactful innovations.
• 🏭 Such a single, large CCD would eliminate Infinity Fabric latency and offer significant L3 cache, potentially transforming Threadripper into a gaming-capable platform.
• 📈 Manufacturing yields for extremely large single CCDs are currently a significant hurdle, explaining AMD's focus on 8-core CCDs.

Real-World Performance and User Experience

• 📊 At high resolutions (4K ultrawide) with maxed-out settings, the CPU difference between a 9950X3D and even a Core Ultra is often imperceptible without an FPS meter.
• ✅ The current asymmetrical 9950X3D offers a good balance for both gaming and multitasking, providing the best of both worlds.
• 🎮 The speaker advocates for a 6-core, 12-thread CPU as the sweet spot for many games, based on testing that showed minimal FPS drops below this core count.