Bamba
This model was released on 2024-12-18 and added to Hugging Face Transformers on 2024-12-19.
Bamba is a 9B parameter decoder-only language model built on the Mamba-2 architecture. It is pretrained in two stages - it starts by training on 2T tokens from the Dolma v1.7 dataset and then trained on an additional 200B tokens from FineWeb and Cosmopedia.
You can find all the original Bamba checkpoints under the Bamba collection.
Click on the Bamba models in the right sidebar for more examples of how to apply Bamba to different text generation tasks.
The example below demonstrates how to generate text with Pipeline, AutoModel, and from the command line.
import torchfrom transformers import pipeline
pipeline = pipeline( task="text-generation", model="ibm-ai-platform/Bamba-9B-v2", dtype=torch.bfloat16, device=0)pipeline("Plants create energy through a process known as")import torchfrom transformers import AutoModelForCausalLM, AutoTokenizer
tokenizer = AutoTokenizer.from_pretrained("ibm-ai-platform/Bamba-9B-v2")model = AutoModelForCausalLM.from_pretrained("ibm-ai-platform/Bamba-9B-v2", dtype=torch.bfloat16, device_map="auto", attn_implementation="sdpa")input_ids = tokenizer("Plants create energy through a process known as", return_tensors="pt").to(model.device)
output = model.generate(**input_ids)print(tokenizer.decode(output[0], skip_special_tokens=True))Quantization reduces the memory burden of large models by representing the weights in a lower precision. Refer to the Quantization overview for more available quantization backends.
The example below uses torchao to only quantize the weights to int4.
import torchfrom transformers import AutoModelForCausalLM, AutoTokenizer, TorchAoConfig
quantization_config = TorchAoConfig("int4_weight_only", group_size=128)tokenizer = AutoTokenizer.from_pretrained("ibm-ai-platform/Bamba-9B-v2")model = AutoModelForCausalLM.from_pretrained( "ibm-ai-platform/Bamba-9B-v2", quantization_config=quantization_config, device_map="auto", attn_implementation="sdpa")
inputs = tokenizer("Plants create energy through a process known as", return_tensors="pt").to(model.device)output = model.generate(**inputs)print(tokenizer.decode(output[0], skip_special_tokens=True))-
Bamba supports padding-free training which concatenates distinct training examples while still processing inputs as separate batches. It can significantly accelerate inference by ~2x (depending on model and data distribution) and reduce memory-usage if there are examples of varying lengths by avoiding unnecessary compute and memory overhead from padding tokens.
Padding-free training requires the
flash-attn,mamba-ssm, andcausal-conv1dpackages and the following arguments must be passed to the model in addition toinput_idsandlabels.position_ids: torch.LongTensor: the position index of each token in each sequence.seq_idx: torch.IntTensor: the index of each sequence in the batch.- Each of the
FlashAttentionKwargscu_seq_lens_q: torch.LongTensor: the cumulative sequence lengths of all queries.cu_seq_lens_k: torch.LongTensor: the cumulative sequence lengths of all keys.max_length_q: int: the longest query length in the batch.max_length_k: int: the longest key length in the batch.
The
attention_maskinputs should not be provided. TheDataCollatorWithFlatteningprogrammatically generates the set of additional arguments above usingreturn_seq_idx=Trueandreturn_flash_attn_kwargs=True. See the Improving Hugging Face Training Efficiency Through Packing with Flash Attention blog post for additional information.from transformers import DataCollatorWithFlattening# Example of using padding-free trainingdata_collator = DataCollatorWithFlattening(tokenizer=tokenizer,return_seq_idx=True,return_flash_attn_kwargs=True)
BambaConfig
Section titled “BambaConfig”[[autodoc]] BambaConfig
BambaModel
Section titled “BambaModel”[[autodoc]] BambaModel - forward
BambaForCausalLM
Section titled “BambaForCausalLM”[[autodoc]] BambaForCausalLM - forward