diff --git a/rocksdb/CMakeLists.txt b/rocksdb/CMakeLists.txt
new file mode 100644
index 0000000..74a1317
--- /dev/null
+++ b/rocksdb/CMakeLists.txt
@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 4.0)
+project(rockseb_bench)
+
+set(CMAKE_CXX_STANDARD 23)
+
+add_executable(rockseb_bench main.cpp
+        instant.h)
+set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")
+target_compile_options(rockseb_bench PRIVATE "-flto")
+target_link_libraries(rockseb_bench rocksdb)
diff --git a/rocksdb/instant.h b/rocksdb/instant.h
new file mode 100644
index 0000000..b3f1c3a
--- /dev/null
+++ b/rocksdb/instant.h
@@ -0,0 +1,55 @@
+#ifndef INSTANT_20231013102058
+#define INSTANT_20231013102058
+
+#include <chrono>
+
+namespace nm
+{
+class Instant {
+public:
+	static Instant now()
+	{
+		return { std::chrono::steady_clock::now() };
+	}
+
+	auto elapse_usec()
+	{
+		return diff().count() / 1e3;
+	}
+
+	auto elapse_ms()
+	{
+		return diff().count() / 1e6;
+	}
+
+	auto elapse_sec()
+	{
+		return diff().count() / 1e9;
+	}
+
+	auto elapse_min()
+	{
+		return elapse_sec() / 60.0;
+	}
+
+	void reset()
+	{
+		*this = now();
+	}
+
+private:
+	using timepoint = std::chrono::steady_clock::time_point;
+	Instant(timepoint now) : tp_ { now }
+	{
+	}
+
+	auto diff() -> std::chrono::duration<double, std::nano>
+	{
+		return std::chrono::steady_clock::now() - tp_;
+	}
+
+	timepoint tp_;
+};
+} // namespace nm
+
+#endif // INSTANT_20231013102058
diff --git a/rocksdb/main.cpp b/rocksdb/main.cpp
new file mode 100644
index 0000000..55f975a
--- /dev/null
+++ b/rocksdb/main.cpp
@@ -0,0 +1,119 @@
+#include <rocksdb/cache.h>
+#include <rocksdb/db.h>
+#include <rocksdb/options.h>
+#include <rocksdb/utilities/optimistic_transaction_db.h>
+#include <rocksdb/utilities/transaction.h>
+#include <rocksdb/utilities/transaction_db.h>
+
+#include <algorithm>
+#include <barrier>
+#include <filesystem>
+#include <format>
+#include <iostream>
+#include <random>
+#include <string>
+
+#include "instant.h"
+
+int main()
+{
+	std::string db_root = "/home/abby/rocksdb_tmp";
+	std::filesystem::remove_all(db_root);
+	rocksdb::Options options;
+	options.disable_auto_compactions = true;
+	options.create_if_missing = true;
+	options.max_write_buffer_number = 10;
+	options.target_file_size_base = 64 << 20;
+	options.write_buffer_size = 64 << 20;
+	options.level0_file_num_compaction_trigger = 500;
+	options.max_bytes_for_level_base = 2 << 30;
+	constexpr size_t count = 100000;
+	constexpr size_t workers = 4;
+	auto ropt = rocksdb::ReadOptions();
+	auto wopt = rocksdb::WriteOptions();
+	std::vector<std::thread> wg;
+	std::vector<std::vector<std::string>> keys {};
+	rocksdb::OptimisticTransactionDB *db;
+	std::cout << "db_root " << db_root << '\n';
+	auto s = rocksdb::OptimisticTransactionDB::Open(options, db_root, &db);
+	assert(s.ok());
+	std::string val(1024, 'x');
+
+	for (size_t tid = 0; tid < workers; ++tid) {
+		std::vector<std::string> key {};
+
+		for (size_t i = 0; i < count; ++i) {
+			auto tmp = std::format("key_{}_{}", tid, i);
+			tmp.resize(1024, 'x');
+			key.push_back(std::move(tmp));
+		}
+		keys.emplace_back(std::move(key));
+	}
+
+	for (size_t tid = 0; tid < workers; ++tid) {
+		auto ks = &keys[tid];
+		wg.emplace_back(
+			[&]
+			{
+				for (auto &x : *ks) {
+					auto kv = db->BeginTransaction(wopt);
+					kv->Put(x, x);
+					kv->Commit();
+					delete kv;
+				}
+			});
+	}
+
+	for (auto &w : wg) {
+		w.join();
+	}
+
+	delete db;
+	wg.clear();
+
+	auto sts =
+		rocksdb::OptimisticTransactionDB::Open(options, db_root, &db);
+	assert(sts.ok());
+	std::barrier g { workers };
+	auto b = nm::Instant::now();
+	std::mutex mtx {};
+	std::atomic<uint64_t> operation { 0 };
+
+	for (size_t tid = 0; tid < workers; ++tid) {
+		auto ks = &keys[tid];
+		wg.emplace_back(
+			[&]
+			{
+				g.arrive_and_wait();
+
+				std::string val;
+				if (mtx.try_lock()) {
+					b = nm::Instant::now();
+					mtx.unlock();
+				}
+
+				for (auto &x : *ks) {
+					auto kv = db->BeginTransaction(wopt);
+					kv->Get(ropt, x, &val);
+					kv->Commit();
+					delete kv;
+				}
+				operation.fetch_add(count,
+						    std::memory_order_relaxed);
+			});
+	}
+
+	for (auto &w : wg) {
+		w.join();
+	}
+
+	printf("thread %ld\niterations %ld\nkey_size %ld\nvalue_size %ld\nops: "
+	       "%.2f\n",
+	       workers,
+	       count,
+	       keys[0][0].size(),
+	       val.size(),
+	       static_cast<double>(operation.load(std::memory_order_relaxed)) /
+		       b.elapse_sec());
+	delete db;
+}
diff --git a/src/main.rs b/src/main.rs
index a63bcde..3843bd4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -64,7 +64,7 @@ fn main() {
     opt.tmp_store = true;
     // make sure there's no remote indirection
     opt.max_inline_size = 4096;
-    opt.cache_capacity = 3 << 30; // this is very important for large key-value store
+    // opt.cache_capacity = 3 << 30; // this is very important for large key-value store
     let db = Mace::new(opt.validate().unwrap()).unwrap();
 
     let value = Arc::new(vec![b'0'; args.value_size]);
@@ -163,12 +163,10 @@ fn main() {
 
     // println!("{:<20} {}", "Test Mode:", args.mode);
     // println!("{:<20} {}", "Threads:", args.threads);
-    // println!("{:<20} {total}", "Total Ops:");
-    // println!("{:<20} {:.2}s", "Duration:", duration.as_secs_f64());
-    // println!("{:<20} {ops:.2}", "OPS:");
+    // println!("{:<20} {}", "Iterations", args.iterations);
     // println!("{:<20} {}B", "Key Size:", args.key_size);
     // println!("{:<20} {}B", "Value Size:", args.value_size);
-
+    // println!("{:<20} {ops}", "Total Ops:");
     // if args.mode == "mixed" {
     //     println!("{:<20} {}%", "Insert Ratio:", args.insert_ratio);
     // }