diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
index 537a1c18..4c1ba3b9 100644
--- a/.github/workflows/benchmark.yml
+++ b/.github/workflows/benchmark.yml
@@ -34,3 +34,27 @@ jobs:
         with:
           mode: instrumentation
           run: uv run pytest tests/test_benchmark.py --codspeed
+
+  memory-benchmarks:
+    name: Run memory benchmarks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@c771a70e6277c0a99b617c7a806ffedaca235ff9 # v9.0.0
+        with:
+          python-version: "3.13"
+          enable-cache: true
+
+      - name: Install dependencies
+        run: scripts/install
+        shell: bash
+
+      - name: Run the benchmarks
+        uses: CodSpeedHQ/action@f99becdce5e5d51fd556489ebef684f4ecfd6286 # v4.18.5
+        with:
+          mode: memory
+          run: uv run pytest tests/test_benchmark_memory.py --codspeed
diff --git a/pyproject.toml b/pyproject.toml
index 898503ee..fc432a3a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,12 +79,12 @@ filterwarnings = [
 markers = [
   "copied_from(source, changes=None): mark test as copied from somewhere else, along with a description of changes made to accommodate e.g. our test setup",
   "network: marks tests which require network connection. Used in 3rd-party build environments that have network disabled.",
-  "benchmark: marks CodSpeed benchmark tests under tests/test_benchmark.py.",
+  "benchmark: marks CodSpeed benchmark tests under tests/test_benchmark*.py.",
 ]
 
 [tool.coverage.run]
 source_pkgs = ["httpx2", "httpcore2", "tests"]
-omit = ["src/httpcore2/httpcore2/_sync/*", "tests/test_benchmark.py"]
+omit = ["src/httpcore2/httpcore2/_sync/*", "tests/test_benchmark*.py"]
 
 [tool.coverage.report]
 exclude_also = [
diff --git a/tests/test_benchmark_memory.py b/tests/test_benchmark_memory.py
new file mode 100644
index 00000000..4beb0cf6
--- /dev/null
+++ b/tests/test_benchmark_memory.py
@@ -0,0 +1,44 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import hpack
+import hyperframe.frame
+import pytest
+
+import httpcore2
+
+if TYPE_CHECKING:
+    from pytest_codspeed import BenchmarkFixture
+
+pytestmark = pytest.mark.benchmark
+
+H2_WINDOW = 2**31 - 1
+H2_BODY = b"x" * (8 * 1024 * 1024)
+
+
+def _h2_server_frames() -> list[bytes]:
+    return [
+        hyperframe.frame.SettingsFrame(
+            settings={hyperframe.frame.SettingsFrame.INITIAL_WINDOW_SIZE: H2_WINDOW}
+        ).serialize(),
+        hyperframe.frame.WindowUpdateFrame(stream_id=0, window_increment=H2_WINDOW - 65535).serialize(),
+        hyperframe.frame.HeadersFrame(
+            stream_id=1,
+            data=hpack.Encoder().encode([(b":status", b"200")]),
+            flags=["END_HEADERS"],
+        ).serialize(),
+        hyperframe.frame.DataFrame(stream_id=1, data=b"", flags=["END_STREAM"]).serialize(),
+    ]
+
+
+def test_bench_http2_send_large_body(benchmark: BenchmarkFixture) -> None:
+    origin = httpcore2.Origin(b"https", b"example.com", 443)
+
+    def send() -> int:
+        stream = httpcore2.MockStream(_h2_server_frames())
+        with httpcore2.HTTP2Connection(origin=origin, stream=stream) as conn:
+            response = conn.request("POST", "https://example.com/", content=H2_BODY)
+            return response.status
+
+    assert benchmark(send) == 200