Cost & Sizing
The on-prem AI math, with the parts vendors skip.
On-prem AI is either dramatically cheaper than APIs or an expensive mistake, and the difference is scoping. Here is the honest cost model: what the hardware really needs to be, where the break-even sits, and the line items that surprise teams in month six.
Hardware by model class (planning numbers)
Exact sizing depends on quantization, context length, and concurrency, which is why we benchmark before you buy. But for planning:
- 7-9B models, quantized: one 24-48GB GPU (workstation or single server class) serves a departmental workload
- 30-70B models: 2 to 4 datacenter-class GPUs for real concurrency; one high-memory GPU for light use
- Frontier-scale open models (100B+): multi-GPU nodes; justified only when benchmarks show smaller tuned models genuinely fail your task
- Embedding + reranking for RAG: near-free by comparison; runs beside the LLM or on CPU
Self-hosting vs API: where break-even actually sits
API pricing is linear forever; hardware is a step function that then runs at the cost of electricity and ops. The crossover depends on token volume: light experimentation stays cheaper on APIs, while sustained production workloads (RAG over busy teams, coding assistants, batch document processing) typically cross within the first year, after which self-hosting runs at a fraction of the API bill.
The variable that dominates the math is not the GPU price; it is whether your workload is steady. Bursty, occasional use favors APIs and hybrid routing. All-day-every-day use favors owned hardware emphatically. Our sizing engagement produces this curve for your actual traffic instead of a generic chart.
The three line items teams forget
First: evaluation and data engineering. The model is free; making it good at your task is the project, and it costs engineering weeks, not GPU dollars. Second: day-2 operations, meaning patching, model refreshes, and drift monitoring, at roughly a fraction of an FTE once the runbooks exist (we train your team or run it with you). Third: the failed-pilot tax of skipping benchmarking and buying hardware for a model that was never the right one. It is the most expensive item on this page and entirely avoidable.
Where the savings compound
Beyond the per-token math: fine-tuned small models cut token counts by needing less prompting; owned infrastructure means experimentation is free at the margin, so teams actually iterate; and there is no per-seat pricing, so rolling the assistant to 400 people costs the same electricity as 40. For regulated industries, add the category that matters most: workloads that could never use an API at any price become possible at all.
Straight answers
Can we use hardware we already own?
Often, yes. Existing virtualization clusters with GPU capacity, engineering workstations, or render farms can host pilot and even production workloads for smaller models. We inventory what you have before recommending anything new.
What does a NetRay sizing engagement include?
Workload analysis from your real or projected traffic, benchmarking of 2 to 3 candidate models on your tasks and target hardware, the self-host vs API break-even curve for your volume, and a bill of materials with total cost of ownership over three years. You get the math whether or not you build with us.
Do we need a data center?
No. Most deployments are one to four rack units in a server room you already run. Air-gapped and multi-site deployments add requirements, but 'on-prem AI' for most companies means a short row of GPUs beside the ERP servers.
How do electricity and cooling factor in?
A single-GPU inference server draws comparable power to a few high-end workstations; a 4-GPU node is a noticeable but ordinary line on a server-room power budget. We include power and cooling in the TCO model so there are no month-six surprises.
Get the break-even math for your workload.
One conversation about your traffic and tasks, and we'll model the hardware, the TCO, and the crossover point. No purchase required to get the numbers.
Request the cost modelFree AI workshops available. A founder reads every message.