Quick Analysis of Fireball Support Gems

Intro:
Modifiers that increase area damage and projectile damage increases both the on-hit damage and the burning damage of fireball. This means that a fireball that normally hits for 50 and burns for 10/sec will, with 100% more area damage, hit for 100 and burn for 40/sec. The result of this area damage modifier leads to

(100 + 40*4)/(50 + 10*4) = 2.9

nearly three times the original damage. Similar magnitudes can be found with projectile damage modifiers. Such modifiers are considered to "double-dip" as they contributes to 2 separate sources of damage.

We want to compare the magnitudes of damage of the Concentrated Effect and Slower Projectile support gems (which double dip) to the Fire penetration and Inc. Burning Damage support gems in order to understand which support gem is more efficient at supporting fireball damage. We did so at various gem levels and at various monster resistances. Mainly we are interested if the double dipping of Conc Effect and Slower Proj would outpace Fire Pen.

Data:
All values from the wiki.



Damage is the sum of the initial hit + burning damage. We assume 100% ignition chance.

Analysis:
Concentrated Effect provided the most amount of damage at all gem levels and all monster resistances. Even on a Searing Touch Staff, Conc. Effect wins.

Slower Projectiles only outpaces Fire Penetration when uncapped monster resistance is less than 15% and more than 96%. This is because Fire Penetration does very little when uncapped monster resistance is very high such as in fire resist Maps with normally fire resistant mobs. With a Searing Touch, between 12% and 96% Fire Penetration does best.

Interestingly, Controlled Destruction, ignoring crit modifiers, has identical behavior as slower projectiles, even though it does not contribute to burning damage.

At all other resistance levels (including levels where resistances are negative due to double curse) Slower Proj is better (not shown in image).

Inc. Burning Damage is the least effective of the 4 (not shown in image).

TLDR:
Conc Effect > Fire Pen >= Slower Proj = Controlled Destruction >>>>>>>>>> Increased Burning Damage.

Resources

Excel sheet used to calculate this is found here. I recommend downloading it as opposed to using Google Docs.

This is an old thread, so not sure if you'll be around to read this, but just wanted to say thanks for your efforts in putting this analysis together.

I was interested in using Concentrated Effect for my Fireball. However wasn't sure if Conc Eff only involved secondary AoE damage, and not the Fireball's main impact itself.

Just checked, and it looks like it says it on the wiki too -- full spell damage applies to enemies in AoE. But it's good to see the actual damage comparisons here.

I'm guessing Elemental Focus isn't the best choice for Fireball and probably falls somewhere between Controlled Destruction and Increased Burning Damage.

Elem Focus gives 5% more damage than Cont Destr (49% vs 44%), but totally removes any possible ignites. And while Cont Destr didn't buff the burning DoT, since it's more spell damage and not more elem damage/fire damage, at least the ignites could still happen.

And Fireball has a pretty high ignite chance, so it's kind of a waste to remove all burning DoT altogether with an Elem Focus support gem.

The OP contains incorrect info about how fire penetration works. Fire penetration effectively ignores 'overcapping'.

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TLDR:
Conc Effect > Fire Pen >= Slower Proj = Controlled Destruction >>>>>>>>>> Increased Burning Damage.

Consistent with what I've seen.

How does conc effect work if there is only a single target? A single target can only be hit with the projectile and not area component of a fireball assuming no walls or other targets right?

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Vipermagi wrote:

A Fireball that explodes does not deal initial Hit damage, it only deals AoE Damage.

But Piercing, Forking, and Chaining Fireballs deal only initial projectile Hit damage, no Area Damage, right?

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Vipermagi wrote:

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Nephalim wrote:

How does conc effect work if there is only a single target? A single target can only be hit with the projectile and not area component of a fireball assuming no walls or other targets right?

A Fireball that explodes does not deal initial Hit damage, it only deals AoE Damage.

Omg. That makes much more sense.

In that case, is projectile damage being applied to the AoE tagged damage as well?

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Nephalim wrote:

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Vipermagi wrote:

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Nephalim wrote:

How does conc effect work if there is only a single target? A single target can only be hit with the projectile and not area component of a fireball assuming no walls or other targets right?

A Fireball that explodes does not deal initial Hit damage, it only deals AoE Damage.

Omg. That makes much more sense.

In that case, is projectile damage being applied to the AoE tagged damage as well?

It is projectile AoE so yes. It's weird how many hidden tooltip info there is just for this spell.

So fireball has two components:
a projectile hit (projectile tag not affected by conc effect)
an explosion aoe (projectile tag + aoe tag modified by projectile damage and area damage)

This makes it seem like chain or pierce would really hamper fireball's power so I wonder why no one uses fork fireballs then.

Is there a wiki for data like this (the aoe+projectile part)? How would a player possibly be able to derived this from the in game description.