I know this is alot to read but you need to check this out. I was totally blown away at how much money I wasted. Time to ReGem I thinks....
By: Swindley (EU-Frostwhisper)
Basics first:
First of all, each stat has a value on an item.
+1dmg costs 0.855 to increase on itembudget, while +1 spellcrit costs 1. So +dmg is cheaper to increase than +crit. (compare +8 critgems to +9 dmg etc) School specific +dmg costs 0,7. (spellfire uses this formula as far as I know, even if it's 2 schools)
+1 spellhit is also worth +1 on itembudget/level.
You need 22.1 critrating for 1% more to crit and 12.6 +hit for 1% to hit.
Easier to calculate is +1% hit. +1% hit will give you +1% dmg, and is cheap and easy to increase. Aiming for +16% hit should be the goal for raid bosses. It will improve your dps the most for the smallest amount of itemcost. edit: it's actually slightly better than 1%, and also since that missed spell could have crit, giving you 1/3 mana back, it also passively improves efficiency by a little bit.
Now here's the first interesting calc that alot of people are forgetting. People assume 1% more crit will give them 1% more damage. This is wrong. That is assuming you already have 0% crit, which you probably don't.
Assuming you have 30%, which is OK, each +1% to crit will increase the damage on 70% of your spells by 1%.
For full fire that is 70% of 1.1% (with ignite) = 0,827%. Meaning 22.1 crit rating will increase your dps by 0,827%.
For arc/fire, these numbers change a bit, also assuming 30% crit already for easy calculating. For 22.1 crit rating 70% of 1.45 % (spellpower and ignite) 1.010%
This means, crit rating is a little bit more beneficial to arc/fire than full fire, which is no surprise.
But now let's look at full fire and +dmg. Seeing as +dmg gets benefit from all the Fire damage increasing talents (13%) then +1dmg is +1.13 dmg. But people also often forget here that they do not have 0% crit, as the +dmg can also crit. Assuming once again 30% crit rating, +1dmg 1.13 x 1.3 = 1.469
Let's assume you never get coe, only the +15% scorch dmg debuff. Afaik the talents are also multiplicative, meaning +1.469 x 1.15 = 1.689
If you're spamming fireball, add another +5% to the effect +dmg gets (Improved + Empowered fireball is total +105% of your +dmg, damn coefficiency nerf;) (scorch gets +43% for half the cast, obviously a lot worse for DPS)
So each point of +1dmg is worth +1.689dmg while +1 critrating is really worth +0,827 crit rating, assuming 30% already crit rate. (meaning you need ~26.5 crit rating for about 1% total dmg increase)
Meaning +dmg is TWICE as good for increasing your dps as crit rating is. I repeat, TWICE the value. And it's cheaper to increase, as it costs less on itembudget than crit rating does.
Now for another calc, which will be fairly inaccurate. ~+26.5 crit rating will give you +1% more dps. (as full fire) Easy numbers.
How much will then ~+26.5 dmg give in dps increase? First off, with talents and current crit rating, +26.5 dmg converts into +44.75 dmg. (I could even be cheesy and add another +10% to those +dmg numbers, as +dmg is cheaper on itembudget, but I won't, since this is to compare items.)
Now the calcs get a bit harder, as it's assuming so much about your current gear, and how much dps increase 1% is etc.
So on a 3 sec cast fireball: +26,5dmg x 1.689 --> 44,75 /3 = 14.91 dps increase. While 26.5 crit rating will give you +1% more DPS. Meaning you'd have to do 1491+ dps for +1 crit to get better than +1dmg. It's possible, but would take a lot of +dmg for crit to get better. I'm guessing 1000dps is realistic on a static boss fight with none or little movement. (from experience) If your gear is lower, +dmg will get even bigger benefit.
+crit will be better than +dmg eventually on scaling, but at a ridiculously high amount of +dmg.
But as a closing note. Crit is also good for MOE and procs and similar, so shouldn't be ignored. And also, stacking a single stat on an item is more expensive on the itembudget than stacking 2 different ones.
So an item with +50dmg and +20 crit will off course be better than just +60 dmg. (and also help MOE etc)
Edit: I did the same calculations for arc/fire, and I think the conclusion was that at about 1200dps, self buffed only, crit gets better than +dmg. 1200+dps can be hard to pull off through a whole bossfight, but if your +dmg is already stacked sky high, (I'd guess +1300 dmg or more) AND you have the lightning capacitor, then crit will increase your DPS more than +dmg will.
At 40% crit with scorch, which is high, will make the capacitor proc every 11.25 sec on average, adding ~900 dmg average with crits. = +80dps. Although scorching is a bit lower DPS than Fireballing would be, this trinket helps make up for the difference, and you'll be more mana effective as well.
Conclusion: +hit will actually give you highest DPS. increase on raid bosses, up to +16% with talents, while generally you should be stacking +dmg, while getting the odd crit on items when you can. Choosing the same amount of +crit on an item instead of +dmg is generally slightly gimping your DPS in total.
Runed Living Rubies in everything unless the socket bonus is really worth it. Or the new +hit +dmg gems if you can find them, Veiled Noble Topaz.
Math geniouses, I call on you:
So lets convert those formulas to a real world example. Let's take a fire mage with 900 spelldamage, 100 hit rating, and 30% to crit with fire.
+50 spell damage would mean (B+c*(D+n))/(B+c*D) (902.5+1.035*(900+50)) / (902.5+1.035*900) 1885.75 / 1834 = 1.0282 which is 2.82% more DPS.
+50 spell crit rating would translate to 2.26244 more crit chance (1.1*(C+n)+1) / (1.1*C+1) (1.1*(0.3+0.0226244)+1) / (1.1*(0.3)+1) 1.35488684 / 1.33 = 1.0187 which is 1.87% more DPS.
+50 spell hit rating is 3.96825 more hit chance on top of the 7,93651 hit chance the mage already has (0.83+H+n)/(0.83+H) (0,83 + 0,0793651 + 0,0396825)/(0,83+0,0793651) 0,9490476/0,9093651 = 1,0436 meaning a whopping 4,36% more increase in DPS!
|