diff --git a/async_substrate_interface/async_substrate.py b/async_substrate_interface/async_substrate.py
index 91c4ca0..a9249c2 100644
--- a/async_substrate_interface/async_substrate.py
+++ b/async_substrate_interface/async_substrate.py
@@ -11,7 +11,6 @@
 import socket
 import ssl
 import warnings
-from contextlib import suppress
 from unittest.mock import AsyncMock
 from hashlib import blake2b
 from typing import (
@@ -40,7 +39,6 @@
 from websockets.asyncio.client import connect, ClientConnection
 from websockets.exceptions import (
     ConnectionClosed,
-    WebSocketException,
 )
 from websockets.protocol import State
 
diff --git a/async_substrate_interface/types.py b/async_substrate_interface/types.py
index 8878497..842e260 100644
--- a/async_substrate_interface/types.py
+++ b/async_substrate_interface/types.py
@@ -1,11 +1,13 @@
+import bisect
 import logging
+import os
 from abc import ABC
 from collections import defaultdict, deque
 from collections.abc import Iterable
 from contextlib import suppress
 from dataclasses import dataclass
 from datetime import datetime
-from typing import Optional, Union, Any
+from typing import Optional, Union, Any, Sequence
 
 import scalecodec.types
 from bt_decode import PortableRegistry, encode as encode_by_type_string
@@ -17,9 +19,11 @@
 
 from .const import SS58_FORMAT
 from .utils import json
-from .utils.cache import AsyncSqliteDB
+from .utils.cache import AsyncSqliteDB, LRUCache
 
 logger = logging.getLogger("async_substrate_interface")
+SUBSTRATE_RUNTIME_CACHE_SIZE = int(os.getenv("SUBSTRATE_RUNTIME_CACHE_SIZE", "16"))
+SUBSTRATE_CACHE_METHOD_SIZE = int(os.getenv("SUBSTRATE_CACHE_METHOD_SIZE", "512"))
 
 
 class RuntimeCache:
@@ -41,11 +45,45 @@ class RuntimeCache:
     versions: dict[int, "Runtime"]
     last_used: Optional["Runtime"]
 
-    def __init__(self):
-        self.blocks = {}
-        self.block_hashes = {}
-        self.versions = {}
-        self.last_used = None
+    def __init__(self, known_versions: Optional[Sequence[tuple[int, int]]] = None):
+        # {block: block_hash, ...}
+        self.blocks: LRUCache = LRUCache(max_size=SUBSTRATE_CACHE_METHOD_SIZE)
+        # {block_hash: specVersion, ...}
+        self.block_hashes: LRUCache = LRUCache(max_size=SUBSTRATE_CACHE_METHOD_SIZE)
+        # {specVersion: Runtime, ...}
+        self.versions: LRUCache = LRUCache(max_size=SUBSTRATE_RUNTIME_CACHE_SIZE)
+        # [(block, specVersion), ...]
+        self.known_versions: list[tuple[int, int]] = []
+        # [block, ...] for binary search (excludes last item)
+        self._known_version_blocks: list[int] = []
+        if known_versions:
+            self.add_known_versions(known_versions)
+        self.last_used: Optional["Runtime"] = None
+
+    def add_known_versions(self, known_versions: Sequence[tuple[int, int]]):
+        """
+        Known versions are a map of {block: specVersion} for when runtimes change.
+
+        E.g.
+        [
+          (561, 102),
+          (1075, 103),
+          ...,
+          (7257645, 367)
+        ]
+
+        This mapping is generally user-created or pulled from an external API, such as
+        https://api.tao.app/docs#/chain/get_runtime_versions_api_beta_chain_runtime_version_get
+
+        By preloading the known versions, there can be significantly fewer chain calls to determine version.
+
+        Note that because the last runtime in the supplied known versions will be ignored, as otherwise we would
+        have to assume that the final known version never changes.
+        """
+        known_versions = list(sorted(known_versions, key=lambda v: v[0]))
+        self.known_versions = known_versions
+        # Cache block numbers (excluding last) for O(log n) binary search lookups
+        self._known_version_blocks = [v[0] for v in known_versions[:-1]]
 
     def add_item(
         self,
@@ -59,11 +97,11 @@ def add_item(
         """
         self.last_used = runtime
         if block is not None and block_hash is not None:
-            self.blocks[block] = block_hash
+            self.blocks.set(block, block_hash)
         if block_hash is not None and runtime_version is not None:
-            self.block_hashes[block_hash] = runtime_version
+            self.block_hashes.set(block_hash, runtime_version)
         if runtime_version is not None:
-            self.versions[runtime_version] = runtime
+            self.versions.set(runtime_version, runtime)
 
     def retrieve(
         self,
@@ -75,26 +113,35 @@ def retrieve(
         Retrieves a Runtime object from the cache, using the key of its block number, block hash, or runtime version.
         Retrieval happens in this order. If no Runtime is found mapped to any of your supplied keys, returns `None`.
         """
+        # No reason to do this lookup if the runtime version is already supplied in this call
+        if block is not None and runtime_version is None and self._known_version_blocks:
+            # _known_version_blocks excludes the last item (see note in `add_known_versions`)
+            idx = bisect.bisect_right(self._known_version_blocks, block) - 1
+            if idx >= 0:
+                runtime_version = self.known_versions[idx][1]
+
         runtime = None
         if block is not None:
             if block_hash is not None:
-                self.blocks[block] = block_hash
+                self.blocks.set(block, block_hash)
                 if runtime_version is not None:
-                    self.block_hashes[block_hash] = runtime_version
-            with suppress(KeyError):
-                runtime = self.versions[self.block_hashes[self.blocks[block]]]
+                    self.block_hashes.set(block_hash, runtime_version)
+            with suppress(AttributeError):
+                runtime = self.versions.get(
+                    self.block_hashes.get(self.blocks.get(block))
+                )
                 self.last_used = runtime
                 return runtime
         if block_hash is not None:
             if runtime_version is not None:
-                self.block_hashes[block_hash] = runtime_version
-            with suppress(KeyError):
-                runtime = self.versions[self.block_hashes[block_hash]]
+                self.block_hashes.set(block_hash, runtime_version)
+            with suppress(AttributeError):
+                runtime = self.versions.get(self.block_hashes.get(block_hash))
                 self.last_used = runtime
                 return runtime
         if runtime_version is not None:
-            with suppress(KeyError):
-                runtime = self.versions[runtime_version]
+            runtime = self.versions.get(runtime_version)
+            if runtime is not None:
                 self.last_used = runtime
                 return runtime
         return runtime
@@ -110,16 +157,21 @@ async def load_from_disk(self, chain_endpoint: str):
             logger.debug("No runtime mappings in disk cache")
         else:
             logger.debug("Found runtime mappings in disk cache")
-        self.blocks = block_mapping
-        self.block_hashes = block_hash_mapping
-        self.versions = {
-            x: Runtime.deserialize(y) for x, y in runtime_version_mapping.items()
-        }
+        self.blocks.cache = block_mapping
+        self.block_hashes.cache = block_hash_mapping
+        for x, y in runtime_version_mapping.items():
+            self.versions.cache[x] = Runtime.deserialize(y)
 
     async def dump_to_disk(self, chain_endpoint: str):
         db = AsyncSqliteDB(chain_endpoint=chain_endpoint)
+        blocks = self.blocks.cache
+        block_hashes = self.block_hashes.cache
+        versions = self.versions.cache
         await db.dump_runtime_cache(
-            chain_endpoint, self.blocks, self.block_hashes, self.versions
+            chain=chain_endpoint,
+            block_mapping=blocks,
+            block_hash_mapping=block_hashes,
+            version_mapping=versions,
         )
 
 
diff --git a/async_substrate_interface/utils/cache.py b/async_substrate_interface/utils/cache.py
index 24c609c..1ee82b3 100644
--- a/async_substrate_interface/utils/cache.py
+++ b/async_substrate_interface/utils/cache.py
@@ -111,9 +111,9 @@ async def load_runtime_cache(self, chain: str) -> tuple[dict, dict, dict]:
             if not self._db:
                 _ensure_dir()
                 self._db = await aiosqlite.connect(CACHE_LOCATION)
-        block_mapping = {}
-        block_hash_mapping = {}
-        version_mapping = {}
+        block_mapping = OrderedDict()
+        block_hash_mapping = OrderedDict()
+        version_mapping = OrderedDict()
         tables = {
             "RuntimeCache_blocks": block_mapping,
             "RuntimeCache_block_hashes": block_hash_mapping,
diff --git a/tests/unit_tests/test_types.py b/tests/unit_tests/test_types.py
index f2e13b4..928d809 100644
--- a/tests/unit_tests/test_types.py
+++ b/tests/unit_tests/test_types.py
@@ -111,15 +111,15 @@ async def test_runtime_cache_from_disk():
         substrate.initialized = True
 
         # runtime cache should be completely empty
-        assert substrate.runtime_cache.block_hashes == {}
-        assert substrate.runtime_cache.blocks == {}
-        assert substrate.runtime_cache.versions == {}
+        assert len(substrate.runtime_cache.block_hashes.cache) == 0
+        assert len(substrate.runtime_cache.blocks.cache) == 0
+        assert len(substrate.runtime_cache.versions.cache) == 0
         await substrate.initialize()
 
         # after initialization, runtime cache should still be completely empty
-        assert substrate.runtime_cache.block_hashes == {}
-        assert substrate.runtime_cache.blocks == {}
-        assert substrate.runtime_cache.versions == {}
+        assert len(substrate.runtime_cache.block_hashes.cache) == 0
+        assert len(substrate.runtime_cache.blocks.cache) == 0
+        assert len(substrate.runtime_cache.versions.cache) == 0
         await substrate.close()
 
         # ensure we have created the SQLite DB during initialize()
@@ -136,7 +136,7 @@ async def test_runtime_cache_from_disk():
 
         substrate.initialized = True
         await substrate.initialize()
-        assert substrate.runtime_cache.blocks == {fake_block: fake_hash}
+        assert substrate.runtime_cache.blocks.cache == {fake_block: fake_hash}
         # add an item to the cache
         substrate.runtime_cache.add_item(
             runtime=None, block_hash=new_fake_hash, block=new_fake_block