The Historian casts his eyes back over the rich history of the DDS Universe.
Even in the worm-drive era the fact that the DDS were the first to send a ship through the 1000c barrier (using hyperspace drive) in known-space is still a great source of pride and a feat that few have yet emulated. The Dinos have more or less settled on around 900c (and even the latest PTs fall short of that). The Tarbotians are rumoured to have a ship that can reach 1000c but its not known how many they have in service. Other factions like the Clones still fall well short.
The first ship to break the 1000c barrier was the singleton research ship SS Neptune. It was basically built around a new engine (also called Neptune) which came from a DDS Research project in the early 2090s which basically started from scratch with engine design. As Dr Forbidden has told me the Neptune project was a true "clean sheet of paper" project. "We tried to reinvent the spaceship engine, everything was examined from the reaction chamber downwards, everything was stretched, redesigned, enhanced in order to create an engine with vastly more power than had ever been created before."
The original Neptune engine thus powered the Neptune 92X ship, Neptune the ship was rather crude in many ways. It was described by one crewmember as "an engine with a few other things bolted onto it" but this amazing ship managed to break the 1000c barrier in the late 2090s and also helped pave the way for the next generations of DDS warship.
A development of the Neptune engine itself was later used in the Quasar 15A cruiser (though this could not reach 1000c until its ILU). The Meson (which powers the Isometric family) and Gluon which powers the (Panther) are direct descendants of the Neptune. The Panther probably represents the maximum that can be wrung from hyperspace design with a sprint dash speed of 1100c.
The DDS do not plan to try and reach any higher speeds, DDS Research think that 1200c is probably reachable but the massive expense is simply not worth it anymore now that wormdrive can propel a ship at the equivalent of near 5000c!