Exam Room · Advanced GenAI

Cheat Sheet: Model Selection and Inference

July 31, 2026 · 13 min read

Generative AI Development · part of The Exam Room

A fast revision sheet for model choice and inference options across Amazon Bedrock and self-hosted SageMaker.

Services at a glance

Thing What it is Reach for it when
Amazon Nova Micro Text-only, lowest cost and latency in the family High-volume text tasks where speed and price win
Amazon Nova Lite / Pro Multimodal (text and image and video in), Pro is the higher-quality tier You need images or video understood; Pro when quality matters, Lite when cost does
Amazon Nova Canvas Image generation, legacy; EOL 30 Sep 2026 Nothing new; Stability AI took over the image slot
Amazon Nova Reel Video generation, legacy; EOL 30 Sep 2026 Nothing new; Luma Ray 2 took over the video slot
Amazon Titan Amazon text and embeddings models Embeddings for RAG and search; general text
Anthropic Claude Strong general reasoning and long context Complex reasoning, tool use, long documents
Meta Llama Open-weight text models on Bedrock Open-model preference within managed Bedrock
Mistral Efficient text models, some larger reasoning tiers Cost-efficient text; European provider preference
Cohere Text generation plus strong embed and rerank Embeddings and reranking for retrieval
AI21 Labs Jamba Long-context text models Long-context generation
Stability AI Image generation (Stable Image Core / Ultra, SD3.5 Large) The active text-to-image pick; us-west-2 for generation
Luma AI Ray 2 Short video generation, async job to S3 The active text-to-video pick; 5s or 9s, 540p or 720p
On-demand inference Pay per token, no commitment, quota-bound Spiky or unpredictable traffic; getting started
Provisioned Throughput Reserved model units per hour Steady high volume; required for custom and imported models
Batch inference Async S3-to-S3, roughly half the on-demand price Large offline jobs with no latency need
Cross-region inference profile Routes requests across regions for more throughput Bursty load that exceeds a single region’s quota
SageMaker hosting Self-host open or custom models on your endpoints Models not on Bedrock, or full control of serving
Intelligent Prompt Routing Routes within a model family to the cheapest tier meeting a quality bar Mixed request difficulty under one endpoint

Decision rules

  • If the task is text-only and high-volume, start at Nova Micro and only move up if quality falls short.
  • If input includes images or video, you need a multimodal model (Nova Lite/Pro, Claude, others), not Micro or Titan text.
  • If you need to generate images, reach for Stability; for video, Luma Ray 2. Nova Canvas and Nova Reel are legacy, reach end of life on 30 September 2026, and are not a choice for new work.
  • If you need embeddings for RAG, reach for Titan Embeddings or Cohere Embed, not a chat model.
  • If traffic is spiky and low commitment, use on-demand.
  • If volume is steady and high, price out Provisioned ThroughputReserved Bedrock capacity bought by the hour for a fixed term, paid for whether traffic fills it or not. against on-demand.
  • If you fine-tune or import a custom model, you must serve it on Provisioned Throughput.
  • If the job is large and offline with no latency need, use Batch inferenceSubmitting a bulk job of model calls to run asynchronously at a lower per-token price, trading immediacy for cost. for the discount.
  • If a single region’s throughput quota is the limit, enable a Cross-region inferenceLetting a request be served from any of several regions, raising effective throughput and riding out pressure in one of them. profile.
  • If data must stay in one geography, scope the inference profile to same-geography regions and check residency.
  • If the model is not on Bedrock, host it on SageMaker.
  • If a SageMaker endpoint sits idle between bursts, use serverless to scale to zero and accept cold starts.
  • If payloads are large or processing is slow, use SageMaker asynchronous inference with its queue.
  • If you score a whole dataset once with no live endpoint, use SageMaker batch transform.
  • If you host many similar models cheaply behind one endpoint, use a multi-model endpoint.
  • If requests vary in difficulty, put Intelligent Prompt Routing in front and let it pick the cheapest tier that clears the bar.

Traps

  • Nova Micro is text-only; picking it for an image or video task is wrong.
  • Nova Canvas and Nova Reel are on the legacy list; an account with no recent history of calling them is refused access, and both are withdrawn entirely on 30 September 2026, so do not design new work around either.
  • Video generation is asynchronous: Ray 2 runs through StartAsyncInvoke and delivers to S3, so there is no synchronous response to wait on.
  • Provisioned Throughput is not just a cost lever; it is required for custom and imported models, not optional.
  • Batch inference is asynchronous and offline; it does not lower latency for live requests.
  • Cross-region inference profiles move data across regions, which can breach a data-residency requirement.
  • On-demand is quota-bound; hitting throttling means raising quota or moving to Provisioned Throughput, not retrying blindly.
  • SageMaker serverless has cold starts; do not pick it when consistent low latency matters.
  • Enabling model access in the console is a prerequisite; a model you have not enabled will not answer.
  • Model availability differs by region; a model in one region may be absent in another.
  • Bigger is not automatically better; the smallest model that clears the quality bar is usually the right pick on cost and latency.
  • SageMaker batch transform has no persistent endpoint; do not use it for real-time serving.
  • Asynchronous inference is for large payloads and long jobs, not a substitute for provisioned real-time throughput.
  • Fine-tuning changes the model you must provision; you cannot serve a fine-tuned model on plain on-demand.

Say it in one line

  1. Nova Micro is text-only; Lite and Pro are multimodal; Canvas and Reel are legacy, so images come from Stability AI and video from Luma Ray 2.
  2. Titan and Cohere give you embeddings; use them for RAG and search, not chat.
  3. On-demand charges per token with no commitment and is bound by service quotas.
  4. Provisioned Throughput reserves Model unitThe billing block Provisioned Throughput is sold in – one unit delivers a fixed tokens-per-minute rate for a specific model. per hour and is mandatory for custom and imported models.
  5. Batch inference is async S3-to-S3, roughly half price, and offline only.
  6. Cross-region inference profiles raise throughput by spreading load and can carry data-residency implications.
  7. Enabling model access and checking regional availability are prerequisites before any call.
  8. SageMaker real-time serves low-latency traffic on an always-on endpoint.
  9. SageMaker serverless scales to zero and trades cold starts for idle savings.
  10. SageMaker asynchronous inference queues large payloads and long-running jobs.
  11. SageMaker batch transform scores a dataset offline with no persistent endpoint.
  12. Multi-model endpoints host many similar models cheaply behind one endpoint.
  13. Intelligent Prompt Routing routes within a family to the cheapest tier that meets a quality bar.
  14. Pick the smallest model that clears the quality bar; move up only when it does not.

These posts are LLM-aided. Backbone, original writing, and structure by Craig. Research and editing by Craig + LLM. Proof-reading by Craig.