Schnell! Schnell!

Part Dos of my epic posting about spell haste rating.

First off, I'm going to address some of the concerns brought up in the comments on the last post. Delos, the whole 15.?!?? haste rating = 1% only applies to attack speed haste rating. It is not the number for spell haste conversions, but for melee peoples like rogues and warriors. For them, its a whole new can of worms, since auto-attacks don't actually have a cap on their haste ratings.

For spellcasters, its still 21 haste rating, sadly.

And again, I cannot stress this enough. There is NO STAT that should deter you from spell hit rating if you are under the cap. Simply put, there is no stat that is better than spell hit for DPS increases. Get spell hit capped before you even start caring about the rest of the stuff.

And Megan is definitely right. Spell Haste is a wonderful stat for PvP.

I've talked about it before. Mobility is one of the most important things to have in a competitive environment. If your spells take less time to cast, thats less time you're sitting there, self-snared. The GCD be damned, if you have a Paladin casting .8 second Flashes of Light...
Well, its self explanatory. Good luck stopping that cast from getting off.

Anyhoo. Part two.

Spell Haste, if you thought it was confounding before, check out the madness it does to Arcane spells.
Obviously, the easiest example is Arcane Missiles. This channeled spell normally takes 5 seconds to go through the entire spell, and adding spell haste, rather simply, reduces it accordingly. 10% haste rating will reduce it to a 4.5 second, 30% to a 3.5 second channel. And so on. Exactly like we talked about with fireball, an exact DPS increase.

Arcane Blast... is weird. Due to its varying cast times, it has varying returns from spell haste.
Devoid of "Arcane Blast Buffs" the spell has a cast time of 2.5 seconds. For the sake of simplicity, let's assume the 20% haste from Icy Veins.
Devoid of the buff, the spell drops to a 2 second cast speed. Pretty darn good, right there. That's a flat 20% increase in spell damage right there.
But then... Arcane Blast gets faster. 1 buff would normally shave off some time, giving us a new cast speed of 2.17 (the buff note itself is wrong, ignore it. The tooltip states 2.17, and it is far more accurate than the 2.2 the buff claims it is).
So what's 2.17 with a 20% spell haste? That will give us a 1.74 cast time. All mighty fine at this point, still a flat 20% DPS increase. Woot!
So now we have two stacks of the buff. We're now looking at a base cast speed of 1.83 seconds. Toss in the 20% spell haste... we get a 1.46 cast time.

Uh oh. See what just happened there? We dipped into the GCD is what happened there.
With two buffs, that 20% spell haste rating is NOT giving us a flat 20% DPS increase anymore. By dipping into the GCD, we're actually ONLY getting an 18% DPS increase.

Well, shucks.

So, 3 buffs of Arcane Blast now, giving us a new base cast time of 1.5 seconds.

Guess what else lasts 1.5 seconds? Thats right the GCD. With 3 buffs of Arcane Blast, spell haste of any amount has proved itself utterly useless.

So that's Arcane Blast. If you're speccing Arcane, take it with a grain of salt. Arcane Missiles chugs happily along, and Arcane Blast does fine most of the time.


So now we get the "misc" spells.

We're talking stuff like Portals, Evocation, Blizzard, things like that.

Surprisingly, these spells all behave exactly the same way when it comes to spell haste.

The following spells behave, under spell haste effects, exactly like we've discussed before:
Arcane Missiles, Fireball, Arcane Blast, Frostbolt, Flamestrike, Scorch, Pyroblast.

All other mage spells are either instant, and thus are not affected at all, or fall into the "Misc" category.

Which I guess is mislabelled, as they aren't really miscellaneous, just a wee bit odd in their own right.
All these misc cast time spells, Portals to capitals, Blizzard, food summoning spells, etc, benefit from static spell haste effects only. By that I mean, if you have bracers that give 25 spell haste, all these spells will have that cast time reduction. Evocation, for example, will only last 7.88 seconds rather than 8. You still get the exact same amount of mana, it just doesn't quite last as long as a spell. For example, with a static buff of 10%, that 10 second portal to Shattrath will only take 9 seconds (And no, it still does NOT become an instant cast when you use Presence of Mind. At least, not on the current PTR build).

However, these same spells do NOT benefit from buffed spell haste effects. Things like Bloodlust, that buff cast speed, have no change in the cast time of these spells.
Only the static stuff like the 45 spell haste on them pants will.

Think you can pop Icy Veins and have an Evocation that lasts 6.4 seconds? You are sadly mistaken.

On a related note, when is Presence of Mind going to cause Evocation to be an instant cast? Hmm?