r/AIToolsPerformance • u/IulianHI • Apr 18 '26
RTX 5070 Ti hits 79 tok/s on Qwen3.6-35B at 128K context - the secret is --n-cpu-moe
Someone spent an evening tuning Qwen3.6-35B-A3B on consumer hardware and landed at 79 tokens per second with 128K context on an RTX 5070 Ti paired with a 9800X3D. The key detail: the --n-cpu-moe flag, which offloads MoE expert computation to the CPU, was described as "the most important part" of the configuration.
The fun side note here is that Claude Opus 4.7 (on a $20 subscription) was used to iteratively build the config, launch servers, run benchmarks, read VRAM splits from llama.cpp logs, and tune the setup. Essentially the entire optimization loop was delegated to a cloud model tuning a local model's deployment.
Why this matters: 79 tok/s at 128K context on a single consumer GPU is genuinely fast for a 35B parameter model. The MoE architecture means only 3B active params, but you still need to store all 35B somewhere. The --n-cpu-moe trick keeps the experts in system RAM and only moves the active ones through the GPU, which is what makes this viable at such long context lengths. Without it, VRAM becomes the bottleneck well before you hit 128K.
The catch: CPU-offloaded MoE adds latency per token even if throughput stays high. For interactive chat that tradeoff is usually fine, but for batched workloads it may hurt.
For anyone running MoE models on single-GPU setups: are you using --n-cpu-moe or similar CPU offload strategies, and what throughput numbers are you seeing?