Increased Attack Speed:
1-handed weapons generally have a faster attack speed than 2-handed weapons. A lot of people have noticed that disintegrate burns up AP proportional to your attack speed, but are also wondering if their overall damage output is greater.
The disintegrate spell ticks based on your attack speed. The interesting thing is that the AP usage depends solely on your attack speed; what this means is that a 1-hander (1.50 attack speed) with the same weapon DPS as a 2-hander (1.00 attack speed) will use up SIGNIFICANTLY MORE MANA while outputting the same overall DPS.
For me, I use a 0.9 attack speed two-handed mace (970 DPS), the Arcane Presence passive skill, a wizard helm that decreases disintegrate's casting cost by 4, and I've made sure not to have any increased attack speed items on... and I can cast disintegrate infinitely without my AP going down at all.
Some of you may wonder if there's any reason to use a 1-handed weapon at all, when using disintegrate. The additional Chaos Nexus Beams proc relative to your attack speed, so having a higher attack speed means that additional beams should occur more often. Also, when kiting (yes, I know, you laugh when kiting and disintegrate are used in the same sentence), increased attack speed will help. Your casting speed IS proportional your attack speed. When activating the beam, the delay is shorter with increased attack speed. The delay between the deactivation of the beam and your character's continued movement is also shorter, so this allows you to successfully stop beaming and continue running away from mobs. With all increased attack speed items on my character and a weapon with 1.63 attack speed, temporal flux, and boots that increase my movement speed by 12%, I've been able to successfully kite Act 2 Inferno Elite Mob Packs in open areas.
Apparently, people are saying that disintegrate can score criticals, even though the critical numbers don't pop-up when they proc. With the Chaos Nexus Rune, each additional beam has the ability to score a critical and a number will pop-up indicating that the critical has proc'd.
The following passive abilities will directly affect disintegrate: Glass Cannon, Arcane Flux, and Arcane Dynamo (more on this later).
Magic Weapon and Familiar:
Both of these work with disintegrate. The Force Weapon Rune for Magic Weapon has a chance to proc the knockback effect, though I'm not sure what the percentage works out to, it might be 2%, but I'm not certain. With the Chaos Nexus Rune, the additional beams also have the ability to knock back. The other Magic Weapon Runes have not been tested at this time.
The Power of the Storm Rune decreases the cost per tick of disintegrate by 3. I personally only used this for Normal and Nightmare Difficulties; in higher difficulties, I've had to use Force Armor for survival. If you're having trouble with disintegrate costs, try to find a wizard hat on the auction house that gives reduction to disintegrate costs or use a slower attack speed weapon.
Item Mods that Increase Damage:
First off, it's obvious that item DPS increases damage, but what other things increase DPS?
So, apparently, I was wrong about this the first time around. I'm editing this post so that the information is correct.
Critical Hit Damage +%, Critical Hit Chance +%, and Increased Attack Speed +% inflate your damage score (again, you can find this on the bottom of the left-pane in your inventory window). This damage score calculation is a calculation for your "average" melee DPS. Here's the general formula for your spell damage:
Spell Damage =
(1 + Passive Skill Bonus %)
* (1 + Total Intelligence / 100)
* (Average Weapon Damage + Average Bonus Weapon Damage)
So basically, it's made up of three parts: your passive skill % bonus (e.g.: Glass Cannon), your total intelligence, and your Weapon Damage.
The reason that your damage score is inflated so drastically from increased attack speed, is because your casting speed is proportional to your attack speed. So, you WILL do more DPS with faster casts. If your spell damage is constant, and your attacking speed goes up, DPS goes up. But for us kiters, we can't afford to stand there and spam spells. We fire off a spell, run, then fire off another, and then rinse and repeat. Though, faster casting does allow for faster casting activation and recovery times.
Lastly, in general, you want to focus on getting Intelligence. Generally speaking, 1 point of Intelligence will add more spell damage than 1 weapon damage.
I won't go into the mathematics involved, but if you're interested, think back to high school when you learned about the math problem where you had to maximize the area of a garden with only a certain amount of fencing...
Just FYI: % Damage Dealt Converted to Life works with disintegrate.
Most of you are wondering how Arcane Dynamo affects disintegrate. Well, if you build up 5 charges, on your NEXT channel, from the beginning of the channel to the end of the channel, the OVERALL damage of each tick will be increased by 75%. Woah! That's insane damage, you say... yes it is. also note that Arcane Dynamo works with Archon abilities too. If you build up 5 charges, and then activate Archon, the next Archon Ability that you use will be boosted by 75%.
With 30K DPS, no increased attack speed items, Arcane Dynamo, and the Intensify Rune, I can literally sweep the screen in Act 1 Inferno Difficulty and kill mobs easily. In Act 2, my increased attack speed items will put me at about 37k DPS (My 1-handed weapon isn't very strong) and I'll switch out: Intensify Rune -> Chaos Nexus Rune, Arcane Dynamo -> Arcane Flux, Signature Spell (used for Arcane Dyamo) -> Arcane Hydra, and I'll be able to successfully kite most Act 2 Elite Mobs. You absolutely MUST HAVE increased movement speed in order to survive past Act 1 Inferno Difficulty. I haven't managed to beat Act 2 Inferno Difficulty yet, so either I'm not a very skilled player, or a disintegrate build isn't viable, but if someone manages to do it, I give you my congratulations! Anything that has Vortex + Fire Chains just completely pwns me.
All this testing was done by taking out my weapon (since lower numbers are easier to deal with) and equipping the Chaos Nexus Rune so that I'd have some numbers to work with. If anyone can successfully test the Intensify Rune, that'd be awesome.
Please help bump and sticky this post. If there's anything incorrect or anything to add, please post :)