diff --git a/implementations/rust/Makefile b/implementations/rust/Makefile
index 3e49826..684eb45 100644
--- a/implementations/rust/Makefile
+++ b/implementations/rust/Makefile
@@ -2,9 +2,12 @@
 watch:
 	cargo watch -c -x 'test --all-targets -- --nocapture'
 
-bench:
+bench: benches/testdata.bin
 	cargo bench --benches
 
+benches/testdata.bin: benches/testdata.bin.gz
+	gzip -dc $< > $@
+
 clippy-watch:
 	cargo watch -c -x 'clippy --all-targets'
 
diff --git a/implementations/rust/benches/.gitignore b/implementations/rust/benches/.gitignore
new file mode 100644
index 0000000..800aca2
--- /dev/null
+++ b/implementations/rust/benches/.gitignore
@@ -0,0 +1 @@
+testdata.bin
diff --git a/implementations/rust/benches/codec.rs b/implementations/rust/benches/codec.rs
index 5509b5e..a011285 100644
--- a/implementations/rust/benches/codec.rs
+++ b/implementations/rust/benches/codec.rs
@@ -1,5 +1,5 @@
 use criterion::{criterion_group, criterion_main, Criterion};
-use preserves::value::{self, decoder, encoder};
+use preserves::value::{self, decoder, encoder, reader, reader::Reader};
 use preserves::{de, ser};
 use std::io::Read;
 use std::io::BufReader;
@@ -79,9 +79,52 @@ pub fn bench_ser_encoder(c: &mut Criterion) {
     }));
 }
 
+pub fn large_testdata_decoder_with_ann(c: &mut Criterion) {
+    let mut fh = std::fs::File::open("benches/testdata.bin").unwrap();
+    let mut bs = vec![];
+    fh.read_to_end(&mut bs).ok();
+    c.bench_function("decode testdata.bin with annotations", |b| b.iter(|| {
+        let mut r = reader::from_bytes(&bs[..]);
+        while let Some(_) = r.next(true).unwrap() {}
+    }));
+}
+
+pub fn large_testdata_decoder_without_ann(c: &mut Criterion) {
+    let mut fh = std::fs::File::open("benches/testdata.bin").unwrap();
+    let mut bs = vec![];
+    fh.read_to_end(&mut bs).ok();
+    c.bench_function("decode testdata.bin without annotations", |b| b.iter(|| {
+        let mut r = reader::from_bytes(&bs[..]);
+        while let Some(_) = r.next(false).unwrap() {}
+    }));
+}
+
+pub fn large_testdata_encoder(c: &mut Criterion) {
+    let mut fh = std::fs::File::open("benches/testdata.bin").unwrap();
+    let mut vs = vec![];
+    let mut r = reader::from_read(&mut fh);
+    while let Some(v) = r.next(true).unwrap() {
+        vs.push(v);
+    }
+
+    c.bench_function("encode testdata.bin", |b| b.iter_with_large_drop(|| {
+        let mut bs = vec![];
+        let mut e = encoder::Encoder::new(&mut bs);
+        for v in &vs {
+            e.write(&v).unwrap();
+        }
+        bs
+    }));
+}
+
 criterion_group!(codec,
                  bench_decoder_bytes, bench_decoder_file, bench_decoder_buffered_file,
                  bench_encoder);
 criterion_group!(serde, bench_de, bench_ser);
 criterion_group!(codec_then_serde, bench_decoder_de, bench_ser_encoder);
-criterion_main!(codec, serde, codec_then_serde);
+criterion_group!{
+    name = large_testdata;
+    config = Criterion::default().sample_size(10);
+    targets = large_testdata_decoder_with_ann, large_testdata_decoder_without_ann, large_testdata_encoder
+}
+criterion_main!(codec, serde, codec_then_serde, large_testdata);
diff --git a/implementations/rust/benches/testdata.bin.gz b/implementations/rust/benches/testdata.bin.gz
new file mode 100644
index 0000000..4216b79
Binary files /dev/null and b/implementations/rust/benches/testdata.bin.gz differ