Below are the benchmarks for LMDB.
2012-09 Some microbenchmarks comparing it to other embedded databases are here. The tests compare OpenLDAP LMDB against Google LevelDB, SQLite 3, Kyoto Cabinet, and BerkeleyDB. The tests were conducted against multiple filesystems, including btrfs, ext2, ext3, ext4, jfs, ntfs, xfs, and zfs. LMDB is several orders of magnitude faster than everything else for reads, while also being several times smaller. Surprisingly, while LMDB’s focus is read speed, it is also decently fast for writes, and unmatched for bulk load speed.
2013-05 Further testing using Memcached can be seen here. The tests compare LMDB against BerkeleyDB, MySQL 5.6 InnoDB, and pure-memory Memcached. Again, LMDB is multiple orders of magnitude faster than other disk-based storage engines, and is even faster than the pure-memory Memcached in multi-threaded workloads.
2013-05 Tests comparing the read performance of LMDB to BerkeleyDB in OpenLDAP here.
2013-08 A benchmark with HyperDex, using both its original LevelDB-based backend, and with LMDB, is now available here.
2013-09 Additional tests with HyperDex are available here. These tests are longer duration and with smaller records, showing some areas where LMDB is weaker.
2013-11 LDAP server benchmarks showing OpenLDAP using LMDB and BDB, as well as most of the major open source and proprietary directory servers were presented at LDAPCon 2013. Products tested included OpenDJ, 389DS, ApacheDS, and servers from Microsoft, CA, Oracle, and Novell. None of the others are anywhere near as efficient as OpenLDAP on LMDB. The slides are available on Lanyrd.
2014-06 A benchmark with RocksDB and other LevelDB-based engines on In-Memory workloads is available here.
2014-09 Scalability testing for In-Memory workloads, building on the previous tests here.
2014-11 Scalability testing for On-Disk workloads, across a varying range of data sizes here.
2015-02 In-memory testing using different malloc libraries here.
2015-02 In-memory testing using different compression libraries here.