What's the name of your sword? As far as I can tell, max theoretical DPS depends not just on the weapon type (e.g. sword, twin swords, hammer...), but the rarity of the weapon.
In other words, for hammers, that insane Forge of Solus Prime that someone posted earlier will always have way more DPS than other hammers because it's rare/unique. Same goes for the Devastator Drills I posted vs. regular gloves, Star Sabers vs. regular swords, etc. My maxed out SS Star Saber does around 8k DPS, by the way.
Anything that looks cool and/or has a cool/unique name or is named after a character is more likely to be powerful compared to your average burn sword or cryo hammer.
There is, however, no difference in base DPS between two identical weapons at the same level and rank. I'm not even sure rank makes a difference actually. It only allows you to go higher because of the higher level cap. All lvl 5 burn swords will do the same amount of damage, unless one has Defect as one of its attributes (lol bad luck). But even that can be fixed through synthesis by replacing Defect with another attribute.
