This release supports a much larger variety of hardware and multiprocessor systems than previous releases, thanks to updates of ACPI and APIC and ACPI interrupt routing support. Hammer volumes can now deduplicate volumes overnight in a batch process and during live operation. The ‘hammer dedup-simulate’ command can be used to estimate space savings for existing data. DragonFly now uses gcc 4.4 as the default system compiler, and is the first BSD to take that step. DragonFly now offers significant performance gains over previous releases, especially for machines using AHCI or implementing swapcache(8).