Blackwell Unleashed: Qwen3.8-27B Hits 785 tok/s Prefill on RTX PRO 4000 with 128K Context
A recent benchmark shared on Reddit’s LocalLLaMA community reveals the raw power of the NVIDIA RTX PRO 4000 Blackwell (24GB). Using the NInfer framework, a developer successfully ran Qwen3.8-27B with a massive 128K context window, achieving a blistering 785 tok/s prefill speed and 67 tok/s MTP3 decoding.
- ▶ Architectural Synergy: By leveraging the Blackwell-native sm_120a instruction set and CUDA 13.3, the RTX PRO 4000 delivers enterprise-grade throughput even under a strict 145W power envelope.
- ▶ Context Optimization: The use of specialized NInfer forks, originally designed for the 5060 Ti/Blackwell family, highlights how cooperative scheduling based on actual SM counts can maximize 24GB VRAM for long-context tasks.
Bagua Insight
This report is a harbinger of the “Blackwell Era” for local AI. The 785 tok/s prefill rate effectively eliminates the “thinking lag” in RAG pipelines, making real-time document analysis on workstation hardware a reality. The fact that a mid-tier professional card can handle 128K context with Qwen3.8-27B suggests that the upcoming RTX 50-series consumer cards will likely cannibalize the lower-end enterprise market. We are seeing a shift where software optimization (like NInfer’s MTP3 decoding) is finally catching up to hardware capabilities, turning 24GB cards into high-performance inference nodes that rival previous-gen data center GPUs.
Actionable Advice
- Optimize for sm_120a: Developers should prioritize inference engines that support Blackwell’s specific SM architecture to leverage the latest cooperative scheduling improvements.
- Edge AI Strategy: For SMBs and edge deployments, the RTX PRO 4000 Blackwell represents a superior ROI compared to aging Ampere-based enterprise silicon, especially for long-context RAG applications.
- Software Tooling: Keep a close watch on NInfer and similar lightweight inference artifacts; their ability to calculate scheduling based on hardware-specific SM counts is becoming the new standard for squeezing performance out of limited VRAM.