Model reference · open weights

ember

Embeddings llmrails Embeddings 1 build Open weights 3k dl/mo

ember is an open-weight embedding model from llmrails. ember-v1 (FP32) weighs 670 MB; the smallest configuration that runs it is RTX 3060 12 GB.

For self-hosting, compare this build's requirements below with the GPU you plan to rent.

  • Ember is a 335M parameter feature-extraction model developed by llmrails for generating text embeddings.
  • It supports English with a context length of 512 tokens and is released under the MIT license.
  • The model was trained using techniques from RetroMAE and SetFit, achieving an average score of 63.54 on the Massive Text Embedding Benchmark.

Summary of the llmrails/ember-v1 model card, 2026-10-01

What it is

Released byllmrails
Released2023-10-10
Parameters335M
VRAM670 MB for the weights

What it runs on

Memory and cards for ember-v1 (FP32)

670 MBweights, file size
1.1 GBruntime overhead
CardRunsMemory
RTX 3060 12 GBfits11.6 GB
RTX 4060 Ti 16 GBfits15.4 GB
RTX 3090 24 GBfits23.4 GB
RTX 4090 24 GBfits23.4 GB
RTX 5090 32 GBfits31.0 GB
L40S 48 GBfits44.0 GB
A100 80 GBfits78.2 GB
H100 80 GBfits78.1 GB
RTX PRO 6000 Blackwell 96 GBfits93.8 GB
DGX Spark (GB10) 128 GB unifiedfits107 GB
H200 141 GBfits138 GB
B200 180 GBfits176 GB

From the model card

What llmrails says about ember

Read the model card

This model has been trained on an extensive corpus of text pairs that encompass a broad spectrum of domains, including finance, science, medicine, law, and various others. During the training process, we incorporated techniques derived from the RetroMAE and SetFit research papers.

Plans

  • The research paper will be published soon.
  • The v2 of the model is currently in development and will feature an extended maximum sequence length of 4,000 tokens.

Usage

Use with transformers:

import torch.nn.functional as F
from torch import Tensor
from transformers import AutoTokenizer, AutoModel

def average_pool(last_hidden_states: Tensor,
                 attention_mask: Tensor) -> Tensor:
    last_hidden = last_hidden_states.masked_fill(~attention_mask[..., None].bool(), 0.0)
    return last_hidden.sum(dim=1) / attention_mask.sum(dim=1)[..., None]

input_texts = [
    "This is an example sentence",
    "Each sentence is converted"
]

tokenizer = AutoTokenizer.from_pretrained("llmrails/ember-v1")
model = AutoModel.from_pretrained("llmrails/ember-v1")

# Tokenize the input texts
batch_dict = tokenizer(input_texts, max_length=512, padding=True, truncation=True, return_tensors='pt')

outputs = model(**batch_dict)
embeddings = average_pool(outputs.last_hidden_state, batch_dict['attention_mask'])

# (Optionally) normalize embeddings
embeddings = F.normalize(embeddings, p=2, dim=1)
scores = (embeddings[:1] @ embeddings[1:].T) * 100
print(scores.tolist())

Use with sentence-transformers:

from sentence_transformers import SentenceTransformer
from sentence_transformers.util import cos_sim

sentences = [
	"This is an example sentence",
    "Each sentence is converted"
]

model = SentenceTransformer('llmrails/ember-v1')
embeddings = model.encode(sentences)
print(cos_sim(embeddings[0], embeddings[1]))

Massive Text Embedding Benchmark (MTEB) Evaluation

Our model achieve state-of-the-art performance on MTEB leaderboard

Model NameDimensionSequence LengthAverage (56)
ember-v1102451263.54
bge-large-en-v1.5102451263.23
bge-base-en-v1.576851263.05
text-embedding-ada-0021536819160.99

Limitation

This model exclusively caters to English texts, and any lengthy texts will be truncated to a maximum of 512 tokens.

License

MIT

Citation

@misc{nur2024emberv1,
      title={ember-v1: SOTA embedding model},
      author={Enrike Nur and Anar Aliyev},
      year={2023},
}

Quoted from the model card on Hugging Face. The full card is behind the Hugging Face link above.

Benchmarks

Reported results

As published on the model card: the maker's own numbers, not measured by AxForge.

TaskDatasetMetricScore
ClassificationMTEB AmazonCounterfactualClassification (en)accuracy76.060
ClassificationMTEB AmazonCounterfactualClassification (en)ap38.760
ClassificationMTEB AmazonCounterfactualClassification (en)f169.882
ClassificationMTEB AmazonPolarityClassificationaccuracy91.977
ClassificationMTEB AmazonPolarityClassificationap88.635
ClassificationMTEB AmazonPolarityClassificationf191.952
ClassificationMTEB AmazonReviewsClassification (en)accuracy47.938
ClassificationMTEB AmazonReviewsClassification (en)f147.583
RetrievalMTEB ArguAnamap_at_141.252
RetrievalMTEB ArguAnamap_at_1056.567
RetrievalMTEB ArguAnamap_at_10057.076
RetrievalMTEB ArguAnamap_at_100057.080
RetrievalMTEB ArguAnamap_at_352.394
RetrievalMTEB ArguAnamap_at_555.055
RetrievalMTEB ArguAnamrr_at_142.390
RetrievalMTEB ArguAnamrr_at_1057.002
RetrievalMTEB ArguAnamrr_at_10057.531
RetrievalMTEB ArguAnamrr_at_100057.535
RetrievalMTEB ArguAnamrr_at_352.845
RetrievalMTEB ArguAnamrr_at_555.473
RetrievalMTEB ArguAnandcg_at_141.252
RetrievalMTEB ArguAnandcg_at_1064.563
RetrievalMTEB ArguAnandcg_at_10066.667
RetrievalMTEB ArguAnandcg_at_100066.770
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