Dune Book Series Database
Dune
Text
It was a warm night at Castle Caladan, and the ancient pile of stone which had served the Atreides family at home for twenty-six generations bore that cooled-sweat feeling it acquired before a change in the weather. (p.3)
Commentary
The Atreides have lived on Caladan as, at least, a planetary power, for twenty-six generations. Assuming thirty years to a generation, they've been in that castle for 780 years.
Also, it says that the Castle is made of stone! This has interesting implications. Even in the 20th century, most fortifications were made of concrete and steel. For a stone castle to be as well-ventilated and powered as a modern wood-and-concrete house would require impressive technological setup. A ventilation system like that of termite mounds would be helpful.
In the half-light of a suspensor globe, dimmed and hanging near the floor, the awakened boy could see a bulky female shape at his door, standing one step ahead of his mother. (p.3)
They have compact antigravity technology. They also have power sources which can power this antigravity and a light, while still being both small and presumably not heavy.
The colonel bashar planted himself half a pace in front of the Baron, hands on hips. The guard hovered behind him in twitching uncertainty. The Baron noted the absence of salute, the distain in the Sardaukar's manner, and his unease grew. There was only one legion of them locally—ten brigades—reinforcing the Harkonnen legions, but the Baron did not fool himself. That one legion was perfectly capable of turning on the Harkonnens and overcoming them. (p.235)
The Sardaukar are indicated here to be very efficient and skilled soldiers. While later it is stated that they have grown lazy and overconfident, they are clearly still quite dangerous.
The door behind Paul slammed open. He whirled to see reeling violence—shouting, the clash of steel, wax-image faces grimacing in the passage.
With his mother beside him, Paul leaped for the door, seeing Idaho blocking the passage, his blood-pitted eyes there visible through a shield blur, claw hands beyond him, arcs of steel chopping futilely at the shield. There was the orange fire-mouth of a stunner repelled by the shield. Idaho's blades were through it all, flick-flicking, red dripping from them.
Then Kynes was beside Paul and they threw their weight against the door.
Paul had one last glimse of Idaho standing against a swarm of Harkonnen uniforms—his jerking, controlled staggers, the blacl goat hair with a red blossum of death in it. Then the door was closed and there came a snick as Kynes threw the bolts. (p.285)
Duncan Idaho, a swordmaster trained by the Ginaz, is an extremely deadly warrior. In Dune: Messiah it is stated that he killed 19 Sardaukar before falling—likely in under a minute. The passage was probably narrow enough to allow him to fight only about two at a time.