Elemental Damage VS Spell Damage

Hi guys!

I was wondering if: 1) skills like Fireball get more DPS with elemental damage items or spell damage items..can someone explain me how the game's engine works ?

2) Skills like Raise Zombie and Raise spectre are only affected by spell damage or there are other parameters I have to get on my gear (i'm not speaking about uniques nor gems)to increase theri DPS ??

Any help will be appreciated !

all +damage modifers get added together

if your fireball is 100-200 damage lets say.

And you have +50% elemental damage, +50%spell damage, and +20% fire damage.
Your fireball will be 100-200+ 120% damage, or 220-440.

"MORE spell damage" then multiplies into that value. More is attained on rightous fury, pain attainment, concentrated effect. conversely, less adds into this as well. lesser multiple projectiles.


Zombies are not effected by spell damage iirc. Spectres might.


Elemental damage, vs spell damage.

Elemental damage will effect any source of elemental damage. on weapon, on spells, on attacks.
Spell damage will only effect spells. Not attacks.

Now for a witch this is largely interchangeable, as most builds will be elemental spell based. But not completely.
ethereal knives for example is a spell, but deals physical damage. So gains spell damage, but not elemental.
A wand build, will not make use of spell damage, but will elemental likely.
Chaos damage. effected by spell damage, but not elemental, when its on a spell. Added chaos damage for example.

summons have passives that give +minion damage.

Thanks for help mate.. So, supposing i'm using mainly Fireball, spell totem (with added chaos damage and concentrated effects) and zombies i have to premiate spell damage at first and then elemental, i've understood the concept ?