Here we go, just in case.
Okay, people have been going back and forth about this, so I've decided to sum up the difference between the two in one post. Note that I'm impartial; I have never played a character that uses destruction magick, and therefore have no opinion on it. But these are the simple STATS about their damage.
To start, allow me to adress the people that claim the issue can be solved via -100% destruction magicka cost.Allow me to translate this suggestion into an oblivion context:
Person 1: "I cant tank enemies, they hit me a few times and I die. Isn't armor underpowered?"(Not really, just an example)
Person 2: "Can't you enchant your armor for 100% chameleon? Why are you complaining?"
The reason is, obviously(to some of us), that is no different from typing 'tgm' into the console. Why even play if the entire basis for the end game is essentially a tweaked way of accessing a console command?
Now, Moving on to the stats:
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Comparison:
One handed Perks: Armsman(100% damage), Bladeseman(20% chance of doing more critical damage(assume 100% extra damage, so equates to 20% damage increase), Dual flurry(35% extra damage) dual savagery(50% extra damage), Savage Strike(25% damage), Fighting Stance(25% more effecient power strikes). Oh, and they can also do power attacks, that about doubles their damage while they can do them.
Destruction Perks: Destruction(50% more effecient), Augmented Fl/Fr/Sh(50% damage), Dual Casting(20% damage boost, 25% less effecient.)
Culminating in...
One Handed: 400% damage, 1200% damage when using power attacks, and 75% normal stamina usage And did you know you can power attack with even one stamina?
Destruction: 180% damage, and 70% stamina usage.
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One Handed Novice Weapon Stats(first perk used): Iron Sword x2: 17 damage per dual strike with no stamina use, ~25 damage per dual power strike.
Destruction Novice Spell Stats(first perk used): Flames x2: 16 damage/second with 12 magicka/second. No power attack available.
Add a second perk, and we get this:
One Handed Novice Weapon Stats(first perk x2): Iron Sword x2: 20 damage per dual strike with no stamina use, 30 damage per dual power strike.
Destruction Novice Spell Stats(Novice Destruction, Dual Casting): Flames x2: 19 damage/second with 17 magicka/second. No power attack available.
Now, let's jump to the endgame, and no enchantments(single skill only.)
One Handed Mastery Weapon Stats(All Perks): Daedric Sword x2 (100 damage per hit, 300 damage per power strike, power strikes now take 75% of previous stamina and stamina meter is much larger. Assume 500 stamina(most points into stamina) Assume 10 power strikes before depleted: Total damage before depletion: 3000 damage, then damage drops to 100 damage per second)
Destruction Mastery Spell Stats(All perks): Lightning Storm Dual Casting (112.5 damage per second, 59 magicka per second. Assume 500 magicka(most points into magicka), lasts for about 10 seconds, for 1125 damage. Magicka regenerates at 3% per second, base, resulting in 28.125 damage per second once magicka is depleted.)
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Now Include Support Skills(Armorer, Enchanting, Alchemy), but all separate(to avoid absurd alchemy/enchanting stacking)
One Handed Boosts: Legendary Daedric Sword+Smithing= 75% damage boost = 175 base damage, 525 power attack damage. + Alchemy = 30% damage = 220 base damage, 680 power attack damage, + Enchanting = +75% damage = 370 base damage = ~1.1k power attack damage.
Destruction Boosts: Smithing: None. 112.5 damage per second. Alchemy: +30% damage, = 146.25 damage per second, Enchanting = zero magicka cost, making this damage perma.
Final Conclusion, with all forms of enchanting:
One Handed: 370 constant damage, ~1.1k power attack damage every ~3 seconds. Average: 613 damage per second.
Destruction: 146.25 damage per second. No power attacks. 146.25 damage per second.
Final Conclusion, without (possibly broken) enchanting:
One Handed: 680 damage for 10 seconds, followed by 211 damage, with 680 power attack damage, average 367. With stamina potions stabilizes at 680.
Destruction: 146.25 damage per second for roughly six seconds, followed by ~28 damage per second indefinately. With magicka potions, stabilizes at 146.25 damage per second.
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These are the stats. Please use them in the future.
EDIT: Final note on one handed; Because the one-handed skill boosts damage itself, but what it does isn't stated anywhere, i didn't include it in this calculation. Theoretically this could mean it does significantly more, but not less, damage than is stated here.