Diablo – What skills/passives proc Tal Rasha stacks, but are not cast for Etched Sigil

I was just running some tests on attackspeed and dots, and the TL;DR is that Attack Speed is a useless stat for dots.

I was able to add 25% attack speed between a ring and an amulet without effecting any other stats. I had no other bonus attackspeed, but I was wielding a pretty fast ceremonial knife to start with. I did all my testing on the Zombies outside Tristram in hell.

My stats, off the character sheet: Damage: 1273.63 Damage increased by intelligence: 870.00% Damage increased by skills: 0.00% attacks per second: 1.4 Critical Hit chance: 5.00% Critical hit Damage: +50.00%

Equipping my two attackspeed items changed: damage: 1592.04 Attacks per second: 1.75

First I checked locust swarm. I didn't record the order of ticks (which seemed random), only the number of ticks of different numbers.

Without attack speed I saw:

• 15 ticks, 11*200, 4*240, 1*40 = 3200 damage total
• 15 ticks, 5*240, 10 * 200 = 3200
• 16 ticks, 4 * 240, 1 * 40, 11 * 200 = 3200

With attack speed I got:

• 15 ticks, 5*240, 10 * 200 = 3200
• 15 ticks, 2 * 240, 1 * 120, 12 * 200 = 3000 (user error?)
• 16 ticks, 3 * 240, 1 * 80 = 3200
• 16 ticks, 1 * 240, 1 * 160 = 3200

Haunt was a little less clean. Most ticks were 213, but the increments were all still in multiples of 40, and it seemed like the extra 3 damage varies between the casts with different numbers of ticks. Without attackspeed I got:

• 23 ticks, 5*255, 18 * 213 = 5109
• 24 ticks, 1 * 43, 4* 255, 19 * 213 = 5110
• 22 ticks, 10 * 255, 12* 213 = 5106
• 23 ticks, 5 * 255, 18*213 = 5109
• 23 ticks, 5 * 255, 18*213 = 5109
• 24 ticks, 4*255, 1*43, 19 * 213 = 5110

with attackspeed:

• 24 ticks, 1 * 83, 3 * 255 = 5108
• 24 ticks, 1 * 43, 4 * 255 = 43 + 1012 + 4047 = 5110
• 23 ticks, 5 * 255 = 5109
• 23 ticks, 5* 255 = 1265 + 3834 = 5109
• 23 ticks, 1* 128, 7 * 255, 15*213 = 5108

Result: I'm nearly sure I just miscounted that one locusts (counting two different things while kiting even slow moving mobs is harder than it looks :/), and there's what looks like rounding error with the numbers out of haunt, but we were looking for a 25% damage increase, and it's just not there.

According to Bashiok:

...faster speed weapons consume more resource but may do more damage. Channeled skills might still be better with slower weapons though because on a channeled skill, you have as much mobility as you want, so the "mobility" and "overkill" advantages of faster weapons are eroded with channeled abilities, so all you’re left with is increased mana cost for increased damage.

So yes, a faster weapon will cause more skills to tick faster, resulting in you dealing more damage over time, but will result in you using up more resources as you are channeling faster.

Channeling mechanics

Let's use Ray of Frost as an example,

Cost: 20 Arcane Power

Effect: Channel a beam of frost that deals 215% weapon damage as Cold.

Since this is a channeled skill. The resource cost ticks by 10 and drains that much Arcane Power at twice the speed of your weapon. If your attack speed is 1 attack per second, instead of draining 20 Arcane Power once per second, it will drain 10 Arcane Power every half seconds.

Additionally, Since Ray of Frost is a channeled spell. It is broken down into many small attacks that deal a total of 215% weapon damage based on your attack speed. If your attack speed is 1 attack per second, it will deal a total of 215% weapon damage per second.

tl;dr: The faster the weapon attack speed, the faster the drain; slower the weapon attack speed, slower the drain.

Damage-dealing

Assuming two weapons have the same damage, the faster weapon will use up resources faster than the slower one when channeling, but the faster weapon will take less time to do full damage than the slower one.

• An axe at 15 damage and 1.0 attack speed will drain slower. (15 DPS)

• A wand at 15 damage and 1.5 attack speed will drain faster, but will do
  the same damage faster. (22.5 DPS)