diff --git a/invokeai/backend/model_manager/hash.py b/invokeai/backend/model_manager/hash.py
index c4f4165ebf..9ca778a65e 100644
--- a/invokeai/backend/model_manager/hash.py
+++ b/invokeai/backend/model_manager/hash.py
@@ -7,13 +7,12 @@ from invokeai.backend.model_managre.model_hash import FastModelHash
 >>> FastModelHash.hash('/home/models/stable-diffusion-v1.5')
 'a8e693a126ea5b831c96064dc569956f'
 """
-
-import hashlib
 import os
 from pathlib import Path
-from typing import Dict, Union
+from typing import Union
 
-from imohash import hashfile
+from blake3 import blake3
+from tqdm import tqdm
 
 
 class FastModelHash(object):
@@ -28,53 +27,44 @@ class FastModelHash(object):
         """
         model_location = Path(model_location)
         if model_location.is_file():
-            return cls._hash_file_sha1(model_location)
+            return cls._hash_file(model_location)
         elif model_location.is_dir():
             return cls._hash_dir(model_location)
         else:
             raise OSError(f"Not a valid file or directory: {model_location}")
 
     @classmethod
-    def _hash_file_sha1(cls, model_location: Union[str, Path]) -> str:
+    def _hash_file(cls, model_location: Union[str, Path]) -> str:
         """
-        Compute full sha1 hash over a single file and return its hexdigest.
+        Compute full BLAKE3 hash over a single file and return its hexdigest.
 
         :param model_location: Path to the model file
         """
-        BLOCK_SIZE = 65536
-        file_hash = hashlib.sha1()
-        with open(model_location, "rb") as f:
-            data = f.read(BLOCK_SIZE)
-            file_hash.update(data)
-        return file_hash.hexdigest()
-
-    @classmethod
-    def _hash_file_fast(cls, model_location: Union[str, Path]) -> str:
-        """
-        Fasthash a single file and return its hexdigest.
-
-        :param model_location: Path to the model file
-        """
-        # we return md5 hash of the filehash to make it shorter
-        # cryptographic security not needed here
-        return hashlib.md5(hashfile(model_location)).hexdigest()
+        file_hasher = blake3(max_threads=blake3.AUTO)
+        file_hasher.update_mmap(model_location)
+        return file_hasher.hexdigest()
 
     @classmethod
     def _hash_dir(cls, model_location: Union[str, Path]) -> str:
-        components: Dict[str, str] = {}
+        """
+        Compute full BLAKE3 hash over all files in a directory and return its hexdigest.
+
+        :param model_location: Path to the model directory
+        """
+        components: list[str] = []
 
         for root, _dirs, files in os.walk(model_location):
             for file in files:
                 # only tally tensor files because diffusers config files change slightly
                 # depending on how the model was downloaded/converted.
-                if not file.endswith((".ckpt", ".safetensors", ".bin", ".pt", ".pth")):
-                    continue
-                path = (Path(root) / file).as_posix()
-                fast_hash = cls._hash_file_fast(path)
-                components.update({path: fast_hash})
+                if file.endswith((".ckpt", ".safetensors", ".bin", ".pt", ".pth")):
+                    components.append((Path(root, file).as_posix()))
 
-        # hash all the model hashes together, using alphabetic file order
-        md5 = hashlib.md5()
-        for _path, fast_hash in sorted(components.items()):
-            md5.update(fast_hash.encode("utf-8"))
-        return md5.hexdigest()
+        component_hashes: list[str] = []
+
+        for component in tqdm(sorted(components), desc=f"Hashing model components for {model_location}"):
+            file_hasher = blake3(max_threads=blake3.AUTO)
+            file_hasher.update_mmap(component)
+            component_hashes.append(file_hasher.hexdigest())
+
+        return blake3(b"".join([bytes.fromhex(h) for h in component_hashes])).hexdigest()
diff --git a/pyproject.toml b/pyproject.toml
index 26db5a63c7..22a6058bbd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -64,6 +64,7 @@ dependencies = [
 
   # Auxiliary dependencies, pinned only if necessary.
   "albumentations",
+  "blake3",
   "click",
   "datasets",
   "Deprecated",
@@ -72,7 +73,6 @@ dependencies = [
   "easing-functions",
   "einops",
   "facexlib",
-  "imohash",
   "matplotlib",                            # needed for plotting of Penner easing functions
   "npyscreen",
   "omegaconf",