FDE ACADEMY · MODULE 03 · LESSON 01
Serve a model on hardware you chose
From a sized model to a measured endpoint: throughput under concurrency, what happens at the queue, and the difference between a machine that fits the weights and one that serves the users.
- Effort
- Half a day, most of it downloading weights and measuring.
- Skills
- llm-inference · linux
Free and self-paced. No certification is offered.
Before you startYou have completed module 02 lesson 01 and can compute a serving memory figure.
01Fitting is not serving
A model fits when its weights and cache are inside the card’s memory. It serves when it answers your users at an acceptable latency while they are all using it. Those are different tests, and the second one fails on machines that pass the first.
Unified-memory workstations are the clearest example: they hold large models comfortably because they have a lot of memory, and they generate slowly because memory bandwidth rather than capacity is the limit. This site keeps one in the alternatives for that reason and says so, rather than recommending it first.
02Throughput, concurrency and the queue
Measure three things and record the conditions: tokens per second for a single request, time to first token, and what both become at your expected concurrency. A server that produces sixty tokens per second alone and eight per user with ten in flight has told you your capacity, and that is the number that belongs in a design document.
When more requests arrive than can be held in flight they queue, and queueing shows up to users as latency rather than as an error. Know where that threshold is on your hardware before a customer discovers it at nine in the morning.
- Measure at the concurrency you derived from headcount, not at one request.
- Record the model, quantisation, context length and hardware next to every figure, or the figure is unusable.
- A second card is a capacity decision; a smaller model is a quality decision. Try the second one first.
03Choosing the serving stack
There are two families. One optimises for throughput under concurrency and is what you want when a team depends on the deployment. The other optimises for getting a model running in one command and is right for a pilot, a single user, or a machine that is not a server. The recipes here carry both and say which is which.
Pick the simple one for the first slice if it meets your measured target. Complexity you did not need is complexity the customer will have to operate after you leave.
04Do this
PRACTICAL TASK
Run the serving recipe and produce your own capacity figures
Serve a model on the hardware you actually intend to use and produce a short capacity note: throughput alone, throughput at concurrency, and the point where requests begin to queue.
What you need
- The hardware the deployment will use, or the closest rental you can get
- A load-generating script or command that can issue concurrent requests
Steps
- 01
Start from the recipe’s first step and size the model against the card before installing anything.
- 02
Run the throughput-oriented server. Record tokens per second and time to first token for one request.
- 03
Repeat at the concurrency your headcount implies, then at double it. Record both, with the context length you used.
- 04
Find the point where latency rises sharply. That is your queue threshold; write it down with the hardware next to it.
- 05
Compare your figures with the hardware profiles the recipe lists and note where reality differed from the estimate.
You are done when
- A capacity note with six numbers and the conditions they were measured under.
- You can state the concurrency at which your deployment becomes uncomfortable, from measurement rather than estimate.
- You can say why the estimate and the measurement differ, or confirm that they agree.
05Where these facts live
This lesson does not restate anything that is already recorded with its evidence elsewhere on the site. These are the pages it leans on.
- Local LLM serving
Six steps: size, serve, authenticate, gateway, measure — with alternatives for smaller deployments.
- vLLM
The throughput-oriented server used in most self-hosted recipes here.
- Ollama
The one-command alternative the recipes keep for small deployments, with the reason attached.
- A controlled AI learning environment
A self-hosted assistant for six hundred students: the sizing, and what the school gains by serving it itself.
Ticks are stored in your browser only. They are not sent anywhere, they are not attached to an account, and clearing your browser data removes them.