Rig Fit, now for expert streaming: size RAM and NVMe, not just VRAM
A calculator and shared benchmark list that predicts tok/s for MoE models spread across VRAM, RAM and NVMe. Local-LLM buyers pay.
Competitive · 552B DeepSeek on one 4090
Written for: Solo builder
Next step
This week, write the bench-submit CLI that records GPU, RAM, NVMe and tok/s for llama.cpp runs. Seed the leaderboard with the Xolotl and RX 9070 XT numbers and ask both r/LocalLLaMA posters to submit first.
Why now
This changes the earlier Rig Fit card. The bottleneck has moved from VRAM to RAM capacity, PCIe and NVMe read speed, and how often the needed experts are already loaded. Existing calculators, and Llmspeed's speed simulator, assume the weights fit in GPU memory. Buyers are now asking whether to buy 128GB of RAM or a second GPU, and nothing answers that from measured runs.
What became possible
The Xolotl engine runs all 552B of DeepSeek-V4.1-Flash on one RTX 4090 with 90GB DDR4 and an NVMe drive. It gets about 27 tok/s decode by pulling in only the experts each token needs. Another builder runs Qwen 27B at its full 262k context on a 16GB RX 9070 XT at 80+ t/s using adaptive KV streaming.
Three ways in
- Streaming-aware calculator
Enter GPU, RAM, NVMe and model. Get expected decode and prefill speeds, built from crowd-submitted runs rather than VRAM arithmetic.
- Customer
- Hobbyists and small teams planning a local LLM box
- Model
- Free calculator, with hardware affiliate links
- bench-submit CLI
One command runs a standard prompt set on llama.cpp or Xolotl and uploads the hardware profile and results to a public leaderboard.
- Customer
- r/LocalLLaMA tinkerers
- Model
- Open source, which builds the dataset
- Build sheets
Paid, tested parts lists with config flags for target models and contexts, refreshed when a new engine release changes the numbers.
- Customer
- Small agencies buying an office inference box
- Model
- $19 per sheet or $49/year
Competition
Every individual piece already exists. Calculators like llm-cal, LLMSizingTool and ModelFit cover sizing from theory, LocalScore and Llamabench cover crowdsourced tok/s, and vLLM bench serve and llama-benchy cover load testing.
Full competition notes (11 competitors)
Every individual piece already exists. Calculators like llm-cal, LLMSizingTool and ModelFit cover sizing from theory, LocalScore and Llamabench cover crowdsourced tok/s, and vLLM bench serve and llama-benchy cover load testing. That makes a standalone load-test CLI or a standalone calculator a weak product. What I didn't find is anything that combines them. LocalScore's dataset is limited to one user on one GPU and has nothing on concurrency or serving engines. The calculators that do handle concurrency rely on bandwidth math, not measured results. None of them starts from team size or headcount. A realistic opening is a dataset of measured multi-user results, keyed on GPU, model, quant, engine, context length and concurrency. You would collect it with a thin wrapper around vLLM bench serve or a similar tool and use it to drive a recommender that answers questions like "8 people, 32k context, a Qwen-class 30B model". The output would be a parts list plus a launch config that has been tested on that hardware. The paid side most likely to work is installers and consultants: client-ready build reports, validated configs and a certified results badge. Technical founders will mostly use the free open data. The main risks are that LocalScore adds concurrency testing, or that vLLM or llm-cal ships a public results database. A crowdsourced dataset also has a cold-start problem, so you would probably need to fill it yourself by running cloud GPUs at the start.
- llm-cal
The closest match on the sizing side. You give it a Hugging Face model and a GPU, and it estimates KV cache, fleet size, prefill and decode throughput, and concurrency limits, then writes a vLLM or SGLang launch command. All of this is calculated from theory. Nothing is measured, and it has no team-size input.
- LocalScore
An open-source benchmark CLI with a public database of tok/s and TTFT results by hardware. It is the most established crowdsourced dataset I found, but it only tests one user on one GPU. It does not cover concurrency, multi-GPU setups or serving engines like vLLM.
- Llamabench
Described as a crowdsourced platform that maps hardware, quantization and KV cache settings to tok/s. The only source I found was a startup directory listing, so I couldn't confirm how mature it is or how people submit results.
- vLLM bench serve
vLLM's built-in load-test CLI, with --max-concurrency and request-rate controls, aimed at OpenAI-compatible servers. It covers the core load-testing feature for free but does not upload results anywhere.
- llama-benchy
A CLI that benchmarks any OpenAI-compatible endpoint at different context depths. Its feature list mentions concurrency support. It also doesn't contribute results to a shared dataset.
- TrueFoundry LLM Benchmarking
A hosted load tester that ramps up concurrent users and reports throughput, TTFT and inter-token latency. It runs inside their platform, so it isn't a local-first CLI.
- LLMSizingTool
An open-source web tool that estimates VRAM, GPU count, latency and hardware cost (CAPEX) for a target queries per second (QPS). It is close to the build-recommender idea but works from estimates, not measurements.
- ModelFit calculator
Checks whether a model fits in a given amount of VRAM and estimates speed. The site itself says its tok/s figures are estimated from memory bandwidth, not benchmarked.
- Inventive HQ LLM Inference Speed Calculator
Estimates single-user tok/s from memory bandwidth, quantization and context length on consumer GPUs and Apple Silicon. It doesn't model concurrency.
- whichllm
Ranks Hugging Face models against a user's own CPU, GPU and RAM, with estimated tok/s. It answers which model fits your hardware, the opposite question to which hardware fits your team.
- OpenClawDC local LLM hardware guide
An editorial guide to hardware for 5, 10 and 25 users. It shows that installers and consultants are interested in this question, but it is static content, not a tool.
Checked 2026-10-11
Risks
- Xolotl is one hobbyist's engine, so its numbers may not reproduce or last
- Llmspeed and similar tools are close by and could add streaming
- Affiliate and sheet revenue is small
- Results move with every quant and engine release, so the data goes stale quickly
Strong team fit and buildability; market pull is the weak point (5).
tech 6 · pull 5 · space 6 · fit 8 · build 8
Exposed
Companies that could benefit or be threatened. News and context, not investment advice.
Momentum of its main topic
Sources
- Xolotl (Strata based) - DeepSeek-V4.1-Flash (552B) on a single 4090 at ~27 tok/s, Uncensored 1017 quant coming in a couple of daysr/LocalLLaMA
- Qwen 27B (IQ4_XS, Q8/Q4 KV) at full 262k context on a 16GB RX 9070 XT: 80+ t/s decode with Adaptive KV Streamingr/LocalLLaMA
- Show HN: Llmspeed – feel how fast a local LLM runs before you buy the hardwareHacker News
- nvidia/NVIDIA-Nemotron-Labs-Dory1.0-4B-BF16 · Hugging Facer/LocalLLaMA
- DeepSeek V4.1 Flash (1017) Now Leads Open-Weight Modelsr/LocalLLaMA
What happened next
- +7d · 18 Oct 2026 nothing yet. No new product launches, funding, acquisitions, or significant press coverage related to streaming-aware LLM calculators for MoE models with RAM/NVMe considerations were found after October 11, 2026. Existing tools like llmfit and various hardware guides remain, but no evidence of the flagged Rig Fit opportunity materializing in the past week.
Status history
- 2026-10-11 Flagged as buildable