Empire Star Wars Ships : Sith starfighter, Darth Vader's

Two laser cannons, two ion cannons

Galatic Empire

Starfighter interceptor

From the Expanded Universe

After Darth Vader was recover from the Imperial rehabilitation with a new body, his first conveyance was a modified Eta-2 Actis-class interceptor. Its former name of "Jedi starfighter" was outdated, the Dark Lord's new ship was simply dubbed a Sith starfighter. Vader, possessing Anakin's mechanical skills, saw only the technical shortcomings of the black-hued craft.

These limitations were further added by the fact that Vader could not comfortably fit into the cockpit.
This caused Vader to demand a craft better suited to his needs, a development program that produced the TIE Advanced x1