Until November 1996, the only registered version of Duke Nukem 3D was v1.3d. We created a new version that had a new fourth episode, and we changed the version to v1.4 - We also gave that a new name - "The Atomic Edition". In order to upgrade customers who had the registered v1.3d CD, we created a patch that could be purchased - that patch was called "The Plutonium PAK"
PC System Analysis For Duke Nukem 3D: Atomic Edition Requirements
Duke Nukem 3D: Atomic Edition requires a Radeon Xpress 1200 Series graphics card with a Pentium III or Athlon MP processor to reach the recommended specs, achieving high graphics setting on 1080p. To summarise, Duke Nukem 3D: Atomic Edition needs around a 16 year old PC to play at recommended settings.