10 man Vezax hard you can absolutely go Arcane without having to worry. After initially using Frost I switched back to Arcane because I felt like I was gimping the raid with Frost. Arcane was more than able to sustain mana pre-nerfs. Now, with free Missile Barrage procs that proc more often, as well as the 128int trinket from badges which leave me sitting on 29.5k mana, mana isn't a problem at all. On top of this Arcane has vastly superior burst for the Animus (though I find Icy Veins pushes me below the global cooldown so actually can't be used).

I have no experience with 25 man Vezax hard however and I'd imagine it would be more of a struggle depending on how efficient your raid is at dealing with life leech.

It may be "common knowledge" but it's not "intuitively correct". My belief is that many people are still thinking in terms of pre-3.2.2 rotations and just presuming without looking at the math that ABarr is the optimal button to press to break the stack. It's not. However, don't free up the talent point in arcane barrage, there are no serious alternatives for using up your AB stack when you are forced to move. If you can't cast ABarr anymore, then when you have to break a stack to get out of the fire, there's nothing else to use which would benefit from the AB stacks you've built up.

This is just not true. As shown on this thread in post 2853, breaking the stack with AM is far more mana efficient than casting ABarr. The reasons are: firstly that your previous AB could still 40% proc MB, so the AM has 40% chance of being 'free' after all; and secondly the longer cast time of AM means that you are regenerating more mana over the course of the spell than for ABarr. In my gear raid buffed Rawr says it's -28mps for breaking with AM on 4-stack versus 294mps for ABarr.

With regards dps loss of unhasted AM versus ABarr, and still considering that the last AB can still proc MB, then Rawr tells me that breaking stack with ABarr is only 3.5% more dps on average of than breaking with AM.

So you lose 3.5% dps for that one cast, but gain over 320mps. Since you presumably want to break the stacks due to mana considerations, you want to choose the mana-efficient option. So I say don't break your stacks with ABarr.

Arcane Barrage does have another advantage when used to break stacks, it has a 20% chance of proccing missile barrage which could then be used straight away as it is higher dps than restacking arcane blast again.

Well, 20% chance of MBAM which is -180mps (in my gear), so still average mps loss. In terms of dps, an unstacked MBAM is only like 2% more dps than full ABspam4MBAM rotation, so you are arguing that a chance on an average 0.4% dps increase is worth losing 320mps for?

Given the calculations posted comparing AB spam to AB4MBAM and/or fishing until proc, are we saying that the old tactic of blowing all cool downs with IV to burn as much mana as possible and then hitting evo on the last tick is no good?
the only way i could see this happening is if we can sustain high DPS cycles with no need to evo at all (unless theres a handy pause in fighting).
i was originally worried that the lower buff time for AB stacks would mean that i cant go a whole evo (at max AB stack) and then hit missiles at the end to use the buff. i think this is just about managable though...

I'm not arguing, I vary what I use depending on mana fight phases etc.

I was just stating something that hadn't been mentioned

This is intriguing. I'm finding that with IV+Scale of Fates+Heroism, its a challenge to hit the cast keys fast enough. Does anyone know what that point is at which haste rating goes beyond the global cooldown for the primary arcane spells? If IV becomes a waste at some point, it would seem to change the spec options substantially. After all, isn't the primary benefit of dipping into frost at all is to get IV?

From a post in a different thread:

Even if you were to get over 876 haste, I'd think the spec wouldn't change "substantially". Don't forget that you can skip Arcane focus in the first tier for pushback protection/lower threat and pick up elemental precision instead, or EP gives you more options for gear if you're lacking +hit. Should you be below the GCD during heroism, you can always use Icy Veins outside of heroism for another DPS boost. Frost warding / ice shards aren't horrible talents either, depending on the encounter.

57 points in Arcane is enough to pick up *most* of the important talents, and the fire tree doesn't have much to offer for arcane.

So im playing around a bit with Rawr and finds out that Abyssal Rune (84 haste, 590sp/10 sec on hit) that drops from Toc normal scores way higher than the Pvp trinket from wintergrasp that got static 111SP on it and i wonder why. Isnt 111 static spellpower way better than a chance on hit trinket for Arcane?

Rawr should also show you that in most higher gear sets haste is valued slightly over SP. The static haste + the spell power proc makes it better. There are about 45 current posts asking almost the exact same question.

I think the usefulness of that would be that you can use IV in one part of the fight Hero/Lust on another and Pot Of speed on another giving you a huge total time of gcd haste cap casting

If you're concerned with MPS you should cast unhasted AM. If you're concerned with DPS you should continue fishing for MBAM procs. If you're concerned about needing to move (possibly from being in some sort of fire) and losing your AB4 stack, you should clear with ABarr.

From personal experience with bad RNG MBAM procs, I still just cast AB and spam it until I get MBAM. The only time I ever use ABarr is whenever I need to move somewhere. You shouldn't be having any mana issues with ABx4 spamming since we have 2 min evocates and our mana gems.

But from what I've been reading the goal is to avoid evocate because it is a dps loss. Unless you have time between phases of course.

The mps and dps explanation makes sense to me. I'm trying to figure out if ABarr is optimal over unhasted AM if you're on a particular fight where you are trying to balance the two and are not yet low on mana. I would think that going into new encounters this may be the case for some mages. I would assume that familiarity with the fight would eliminate this type of uncertainty. Of course that's just my assumption and is very likely flawed.

Anyone know if the macro:

/cast [nochanneling:Arcane Missiles] Arcane Blast

is undoubtedly the best way to cast Arcane Blast without clipping your last missile? I have been arcane for over a year now (never swapped because it was superior pre 3.2.2), and feel that the 5th missile is actually cast before the channeling is finished. My shadowpriest friend claims that the last tick of damage from Mind Flay registers right as the cast is finished. I'm wondering if arcane missiles acts similarly, such that you do actually want to wait for the channel to finish. Thanks.

You don't want to use that macro, for optimal DPS, since it forces you to wait until AM has finished client-side, not just server side. Use Quartz, and time your AB just after AM finishes casting, with Quartz' lag bar. The last missile is cast at the end of the cast, server-side, so you can clip it by <latency>ms, and still get the last missile.

What's up with Arcane Explosion? Since I pull aggro and die on half the pulls anyway (I am exaggerating for effect) I decided on a lark recently to just run into melee range and start dropping Arcane Explosions. First off, my DPS went through the roof, and second it seems like I never ran out of mana. I took a little bit more damage from the occasional AoE or cleave, but nothing I couldn't Blink or Iceblock out of.

I don't know the calculation for DPM for Arcane Explosion but it seems to be much higher than the Flamestrike/Blizzard combo I use for my "normal" AOE rotation. So, this begs the question - am I hallucinating? Do we not drop AE's just because we are a "range" class, or because we need to avoid cleaves, or is there a real theorycraft explanation for flamestrike/blizzard over AE? Was it just that I suck at timing my flamestrikes and blizzards?

Clearcasting currently has a change to proc on every target hit by several AoEs, including Arcane Explosion. Thus, it'll have a nearly +30% crit rate, and you'll never run out of mana. There's details in... I think it was the Mage Compendium thread(?), a page or three back.

Sorry if I've missed something obvious, but I don't understand what about the Empowered buff guarantees that you get it on the second Vortex. Could you enlighten me?

You get the buff at 100 stacks of Powering Up. You get 5-10 stacks per orb, and 45-55 per vortex.

So unless you catch like ~7 orbs, you'll get it on the 2nd vortex.

If stacking all 3 brings you below GCD then its higher DPS to use one seperately, I use IV seperately because with 816 haste if Embrace of the spider procs while Bloodlust & IV are up (which it more often than not does) its taking me below GCD.

Not sure on the numbers but it means I can get off more casts that way.

Evocation isn't too much of a DPS lose. As arcane you have the burst to make up for lost time. And with the crazy amounts of haste most arcane mages have(~800), your Evocate doesn't take long at all. You would only be missing out on 2 or 3 casts of AB.