Amazon Nova Multimodal Embeddings vs NVIDIA NeMo Retriever Embedding and Reranking NIMs

Amazon Nova Multimodal Embeddings

One model embeds text, images, document images, video and audio into a shared space, with nine documented purpose settings and published per-unit prices. It runs in US East (N. Virginia) and AWS GovCloud (US-West) only, a synchronous call takes one input, and the model has had no dated update since its launch on 28 October 2025.

NVIDIA NeMo Retriever Embedding and Reranking NIMs

Self-hosted containers with OpenAPI 3.1 files, typed request fields, five embedding output types and a dated end-of-life list. The API has no authentication or rate limiting of its own, production use needs an NVIDIA AI Enterprise licence at $4,500 a GPU a year, and the release notes carry no dates.

Amazon Nova Multimodal Embeddings

1. Call bedrock-runtime in us-east-1 with model ID amazon.nova-2-multimodal-embeddings-v1:0. No other commercial Region serves it
2. Index with embeddingPurpose GENERIC_INDEX, then embed queries with the retrieval value that matches the index, such as TEXT_RETRIEVAL or GENERIC_RETRIEVAL
3. Always send truncationMode with text. It is required, and NONE fails the request when the text is too long
4. Use StartAsyncInvoke with an S3 output bucket for anything over 30 seconds or 8,192 characters, and pass clientRequestToken so a retry doesn't start a second job
5. Keep one embeddingDimension per index. The default is 3072

NVIDIA NeMo Retriever Embedding and Reranking NIMs

1. Send input_type as query or passage on every embedding call. Asymmetric models return HTTP 400 without it, and the wrong value lowers retrieval accuracy per the docs
2. Do not send dimensions and embedding_type together, and send only 2048 or nothing for dimensions on nvidia/nemotron-3-embed-1b
3. Poll /v1/health/ready before the first call. The Docker health check can report unhealthy while the NIM is ready, per the 2.3 known issues
4. Check the image tag on NGC before pulling. The guide uses nemotron-3-embed-1b:2.3, and NGC's record for that image listed tags up to 2.2.2 on 8 October 2026
5. Put a proxy with authentication and TLS in front of port 8000, and sort /v1/ranking results yourself as the request has no top-n field