Single RTX 3090 Ti Runs DeepSeek and Qwen Models at High Decode Speeds
A r/LocalLLaMA user reports running DeepSeek-V4.1-Flash-1017 at about 35 tokens per second and Qwen3.8-Flash-Next at roughly 138–140 tokens per second on a system with one NVIDIA GeForce RTX 3090 Ti and 128 GB of RAM. The post says GPU Unlock was used alongside customized quantization, memory-management, and speculative-decoding configurations. These figures come from one user's setup and have not been independently verified.
The reproducible configuration provides a concrete community data point for testing large mixture-of-experts models on a single consumer GPU, although the reported speeds are not independently confirmed.
I'm sharing this here because this is working way better than it used to a few months ago with older models. I see people here posting slower speeds with much better hardware than mine and hopefully this information helps.
I used gemini-flash to help me setup everything and I asked it to write up the sequence of steps to get me here - happy to provide more details if there's anything missing.
Since I use gentoo some tools/commands might be unfamiliar to you.
My 6 year old hardware:
- OS & CPU Gentoo Linux running on an AMD Ryzen Threadripper 3990X (64 cores, 128 threads).
- System Memory: 128 GB DDR4 RAM.
- GPU: 1 NVIDIA GeForce RTX 3090 Ti (24 GB GDDR6X VRAM, PCIe Gen 4 x16).
- Primary Storage: 4 TB SSD NVMe.
Models Used, Download Sources, and Measured Speeds
| Model | Architecture | Quantization / Files | Download Source | Real Measured Speed |
|---|---|---|---|---|
| DeepSeek-V4.1-Flash-1017 | 552B MoE (40 layers, 384 experts/layer, ~39B active) | XQ / GSQ V2 + rank-1017-085.bin + FP4 KV + Engram NVMe tables | IndrasMirror/DeepSeek-V4.1-Flash-1017-XQ-Uncensored | ~35 tok/s decode (with MTP/DSpark active) |
| Qwen3.8-Flash-Next | 125B MoE + 51B N-gram (GDN + QSA hybrid, ~3.5B active) | pack-qfn45 (4-bit intermediate, DeltaNet linear KV) | [IndrasMirror/Qwen3.8-Flash-Next-Swift-1.5-XQ-Uncensored](https://huggingface.co/IndrasMirror/Qwen3.8-Flash-Next-Swift-1.5-XQ-Uncensored) | ~138–140 tok/s decode |
#GPU Unlock#DeepSeek-V4.1-Flash-1017#Qwen3.8-Flash-Next#NVIDIA GeForce RTX 3090 Ti#AMD Ryzen Threadripper 3990X#Gemini Flash#Xolotl#DSpark