Update the T5 8-bit quantized starter model to use the BnB LLM.int8() variant.

invokeai/backend/model_manager/load/model_loaders/flux.py

@@ -9,7 +9,7 @@ import accelerate
 import torch
 import yaml
 from safetensors.torch import load_file
-from transformers import CLIPTextModel, CLIPTokenizer, T5EncoderModel, T5Tokenizer
+from transformers import AutoConfig, AutoModelForTextEncoding, CLIPTextModel, CLIPTokenizer, T5EncoderModel, T5Tokenizer
 
 from invokeai.app.services.config.config_default import get_config
 from invokeai.backend.flux.model import Flux, FluxParams
@@ -33,7 +33,8 @@ from invokeai.backend.model_manager.config import (
 )
 from invokeai.backend.model_manager.load.load_default import ModelLoader
 from invokeai.backend.model_manager.load.model_loader_registry import ModelLoaderRegistry
-from invokeai.backend.quantization.fast_quantized_transformers_model import FastQuantizedTransformersModel
+from invokeai.backend.quantization.bnb_llm_int8 import quantize_model_llm_int8
+from invokeai.backend.quantization.bnb_nf4 import quantize_model_nf4
 from invokeai.backend.util.silence_warnings import SilenceWarnings
 
 try:
@@ -115,12 +116,33 @@ class T5Encoder8bCheckpointModel(ModelLoader):
             case SubModelType.Tokenizer2:
                 return T5Tokenizer.from_pretrained(Path(config.path) / "tokenizer_2", max_length=512)
             case SubModelType.TextEncoder2:
-                return FastQuantizedTransformersModel.from_pretrained(Path(config.path) / "text_encoder_2")
+                te2_model_path = Path(config.path) / "text_encoder_2"
+                model_config = AutoConfig.from_pretrained(te2_model_path)
+                with accelerate.init_empty_weights():
+                    model = AutoModelForTextEncoding.from_config(model_config)
+                    model = quantize_model_llm_int8(model, modules_to_not_convert=set())
+
+                state_dict_path = te2_model_path / "bnb_llm_int8_model.safetensors"
+                state_dict = load_file(state_dict_path)
+                self._load_state_dict_into_t5(model, state_dict)
+
+                return model
 
         raise ValueError(
             f"Only Tokenizer and TextEncoder submodels are currently supported. Received: {submodel_type.value if submodel_type else 'None'}"
         )
 
+    @classmethod
+    def _load_state_dict_into_t5(cls, model: T5EncoderModel, state_dict: dict[str, torch.Tensor]):
+        # There is a shared reference to a single weight tensor in the model.
+        # Both "encoder.embed_tokens.weight" and "shared.weight" refer to the same tensor, so only the latter should
+        # be present in the state_dict.
+        missing_keys, unexpected_keys = model.load_state_dict(state_dict, strict=False, assign=True)
+        assert len(unexpected_keys) == 0
+        assert set(missing_keys) == {"encoder.embed_tokens.weight"}
+        # Assert that the layers we expect to be shared are actually shared.
+        assert model.encoder.embed_tokens.weight is model.shared.weight
+
 
 @ModelLoaderRegistry.register(base=BaseModelType.Any, type=ModelType.T5Encoder, format=ModelFormat.T5Encoder)
 class T5EncoderCheckpointModel(ModelLoader):

invokeai/backend/model_manager/starter_models.py

@@ -2,7 +2,7 @@ from typing import Optional
 
 from pydantic import BaseModel
 
-from invokeai.backend.model_manager.config import BaseModelType, ModelType
+from invokeai.backend.model_manager.config import BaseModelType, ModelFormat, ModelType
 
 
 class StarterModelWithoutDependencies(BaseModel):
@@ -11,6 +11,7 @@ class StarterModelWithoutDependencies(BaseModel):
     name: str
     base: BaseModelType
     type: ModelType
+    format: Optional[ModelFormat] = None
     is_installed: bool = False
 
 
@@ -54,17 +55,18 @@ cyberrealistic_negative = StarterModel(
 t5_base_encoder = StarterModel(
     name="t5_base_encoder",
     base=BaseModelType.Any,
-    source="InvokeAI/flux_schnell::t5_xxl_encoder/base",
+    source="InvokeAI/t5-v1_1-xxl::bfloat16",
     description="T5-XXL text encoder (used in FLUX pipelines). ~8GB",
     type=ModelType.T5Encoder,
 )
 
 t5_8b_quantized_encoder = StarterModel(
-    name="t5_8b_quantized_encoder",
+    name="t5_bnb_int8_quantized_encoder",
     base=BaseModelType.Any,
-    source="invokeai/flux_schnell::t5_xxl_encoder/optimum_quanto_qfloat8",
-    description="T5-XXL text encoder with optimum-quanto qfloat8 quantization (used in FLUX pipelines). ~6GB",
+    source="InvokeAI/t5-v1_1-xxl::bnb_llm_int8",
+    description="T5-XXL text encoder with bitsandbytes LLM.int8() quantization (used in FLUX pipelines). ~5GB",
     type=ModelType.T5Encoder,
+    format=ModelFormat.T5Encoder8b,
 )
 
 clip_l_encoder = StarterModel(

invokeai/frontend/web/src/features/modelManagerV2/subpanels/AddModelPanel/StarterModels/StartModelsResultItem.tsx

@@ -15,14 +15,14 @@ export const StarterModelsResultItem = memo(({ result }: Props) => {
     const _allSources = [
       {
         source: result.source,
-        config: { name: result.name, description: result.description, type: result.type, base: result.base },
+        config: { name: result.name, description: result.description, type: result.type, base: result.base, format: result.format },
       },
     ];
     if (result.dependencies) {
       for (const d of result.dependencies) {
         _allSources.push({
           source: d.source,
-          config: { name: d.name, description: d.description, type: d.type, base: d.base },
+          config: { name: d.name, description: d.description, type: d.type, base: d.base, format: d.format },
         });
       }
     }