RE: the calculations on the link you shared
Eval. Int. Bonus: ((EvalInt * 3) / 100) + 1
Intelligence Bonus: (INT / 10) (Drop decimals from result)
GM Inscription Bonus: 10% Damage Bonus
Spell Damage Increase: Int. Bonus + Inscr. Bonus + Spell Damage Increase Items*
Total Damage: (Base Damage * Eval. Int. Bonus) * ((Spell Damage Increase / 100) + 1) (Drop decimals from result)
*Mind Blast damage: Base Damage + ((Magery + Intelligence) / 5) (Drop decimals from result)
Assuming that's accurate, and I can't find anything either way to prove it is or isn't, working through it gives you some clues as to common mistakes. Lets run the numbers using an ebolt as example, base damage 12-13.4
- eval int at 100% = 4.0 bonus, at 120% = 4.6 bonus and using the total damage formula above that more than quadruples spell damage all by itself because it is multiplied directly against base damage, no brainer, you need eval to do decent damage.
- Intelligence 100 = a 10.0 bonus. Using the total damage formula above that results in 10 SDI straight up. If you have no inscr bonus or other SDI items that translates into a 1.1 for the SDI side of the total damage formula or with 120 eval a rise from 55 ebolt damage to 60, or about a 5 hit increase per ebolt, or around 8 with 150 intel. Compared to eval bonus int bonus is tiny.
- GM Scribe 10% = an increase in ebolt base damage from 12 to 13.2. After the effects of 120 eval kick in that's an increase from 55 damage to 60 damage, or about the same as having 100 intel. Also not a huge amount.
- 85% SDI - if you put that much on your suit, which is a lot, the formula above would turn a 55 damage ebolt(magery + 120 eval) into a 102 damage ebolt before you include the int bonus and inscription bonus, this is significant.
- Slayer weapon bonus, doubles the damage vs its slayer type but WHAT damage, the total? The base damage before modifiers? I suspect it straight up doubles damage total so it's worth using unless there are a lot of the types of monsters that you will become weaker to around(slayers make you weak to their opposites).
So to recap: If you are doing damage then eval is a must preferably to 120 and after that prioritize with SDI > 10 int = 20 inscription. That means going with SDI on items before int and knowing that 1% SDI = 10 int = 20 inscription.
If I have anything wrong in there feel free to point it out, also I have no idea what the real caps are in game. 150 is cap int, SDI has no cap in PvM and the total bonus possible from all sources not including eval is 300% base damage? If so a normal 55 damage ebolt can not do more than 165 damage after the bonuses are applied... and I have no idea if slayer can make that 330 or not(thief is my main, not mage).
Also, no amount of bonus is going to do any damage if you don't hit the target, How much HCI does a 120 mage need on say.... a peerless boss? Hmm, or is a tamer required for those... so much to learn.