igbinary

Igbinary is a drop in replacement for the standard php serializer. Instead of time and space consuming textual representation, igbinary stores php data structures in compact binary form. Savings are significant when using memcached or similar memory based storages for serialized data. About 50% reduction in storage requirement can be expected. Specific number depends on your data.

Unserialization performance is at least on par with the standard PHP serializer. Serialization performance depends on the "compact_strings" option which enables duplicate string tracking. String are inserted to a hash table which adds some overhead. In usual scenarios this does not have much significance since usage pattern is "serialize rarely, unserialize often". With "compact_strings" option igbinary is usually a bit slower than the standard serializer. Without it, a bit faster.

https://github.com/igbinary/igbinary

PHP serialization is heavily used within Drupal. But Drupal 8 introduced serialization services that could be swapped. This module offers a igbinary based serialization service. If you enable this modules Drupal 8's key value stores will be using igbinary.

Warning: This module is in an early stage! Don't enable it on you're production site at the moment!