I have a couple questions about the arcane rotation,

I know it's arcane blast x 4 and then if missile barrage arcane missiles if it's up, otherwise arcane blast until it is. My question though is if it's not up after 4 and you keep casting arcane blast, but the missiles barrage procs while you are in mid cast do you stop and cast arcane missiles or finish the arcane blast cast? At least in my experience, the proc notification is not exactly instant and certainly can happen after you've started casting another spell.

Also what about if clearcasting procs while you have 4x arcane blast, do you cast a 5th (and mana free) arcane blast or missile barrage arcane missiles and then back to arcane blast?

I'm using quartz for my casting bar and satrina buff frames if it makes and difference. Are there any macros for arcane, or that would help in these situations?

Thank you for your help

Missile Barrage proccs at the end of succesfully casted spell (Arcane Blast or Arcane Barrage). That means that yes, the procc notifcation will not be "instant" - because idealy, you will want to be casting your next spell already.

While in theory, you could do it like this: Cast 4th AB, wait half a second to see if it procced, keep casting, wait again, keep casting etc., this would be incredibly detrimental to your DPS. Every time you interrupt your chaincasting, you lose the time spent waiting, plus a hefty chunk of time to latency. This is why you just keep casting ALL THE TIME. This means that the MBAR-procc will always come up during a cast. As long as that cast is your 4th or beyond, just finish that cast, and then queue up the AM-spell to follow directly after it. Never interrupt a spell to react to a procc, its almost never worth it.
Clearly, this also goes for your clearcasting-question. Though a critting fullstack-AB for no mana is a juicy concept, losing arround half a second overall (at least) of casting is not.

Also, for the specific situation with proccs and running casts, it is pretty much built into the game mechanic, and no addon will help you there. Just make sure that you can properly see the MBAR-procc when it happens.

Use Power Auras. It's the best mod for tracking buffs and procs. Doesn't even have to be updated, you just add in the name of the buff/debuff.

Make it proc, hover, copy the name of the proc, then use power auras, set it as buff, type the name and make yourself a pretty picture, invert it.

Has there been any consensus on the best AOE rotation for Arcane specs in 3.3? According to the Mage Compendium, Flamestrike alternating ranks is the best dps assuming full dot duration, but the recently updated Arcane thread still mentions AP/IV/blizzard + POM/flamestrike.

It was my understanding that FS 9 -> FS 8 -> Blizzard was the best AoE rotation for Arcane. Obviously if you throw CD's into the mix then there it gets a bit different depending on how long you are AoE'ing etc.

For instance if you are going to have a reasonably long AoE fight then your rotation might look like this:

FS 9 -> FS 8 -> PoM -> Blizzard -> CD's -> FS 9 -> FS 8 -> Blizzard

This way your PoM grants your Blizzard the crit bonus, plus you get the insta cast FS 9.

No, as far as I know. With or without Frost Shards that should be the rotation you use.

You really don't get any extra payoff from Flamestrike ranks / Blizzard compared to spamming Arcane Explosion - if anything I've always found Arcane Explosion to yield better results in practice. I only use Blizzard if I'm worried about being in melee.

I have read from many sources in these forums that Sindragosa's Unchained Magic debuff can be circumvented by stacking it really high, and then iceblocking to prevent the damage. I have tried and confirmed that immunity effects such as iceblock can remove the debuff altogether, such that it wouldn't be stacking in the first place. This also means that your iceblock is used 30 seconds earlier, making it available sooner (in P3 or whatever).

Is there something big I am missing, that makes stacking it much more preferable compared to simply using ice block as soon as the debuff is placed upon you?

If the debuff is cast on you again, you don't have iceblock up to clear it and have to throttle your dps. If you keep stacking the debuff and unchained magic is cast on you again, you can continue to stack the buffets until unchained magic expires, then ice block. The upshot is that you can effectively mitigate two of the debuffs before the phase transition. Just a warning: If you are targeted for a frost tomb, the moment the tomb hits, all the stacks will hit you along with the frost tomb damage; so, as a general rule, it's a good idea to block it right before the air phase or even immediately after the second set of debuffs go out per phase. It's also not a bad idea to use your IB in the first ground phase to ensure that you have it up again for phase 3.

I use IB to clear Sindragosa's Unchained Magic debuff stack the first time I face taking the stack damage. Nothing worse than hitting all CD at the start of the fight and being one of the first ppl to get the debuff. Might as well use it to continue to be able to DPS at the start. And, this means it will be up again in P3 to clear a stack then as well when it will really hurt. See above post about cautions on what else will cause the stack to inflict damage. You have time after the debuff ends but before the stack's damage is inflicted to see if you'll be lucky/unlucky enough to get chained with the debuff.

About 5% of the time when I Ice Block an unchained magic, I still take the full damage of the buff being cleared off of me and i end up dieing. IB ends up being on CD as well.
This might be because I am going into a IB and out of it really quickly, but I am not sure how the damage is going through my IB. This bug has forced me to use IB as soon as possible rather then wait to stack multiple debuffs to see if i get another unchained magic. Other mages in my guild have reported this occurring as well.

The backlash happens just slightly after the debuff is removed/cleared so you have to be sure not to cancel your IB too early. As long as you wait a second or so you should be fine, unless they changed something about the backlash mechanic.

World of Logs - Real Time Raid Analysis

[20:16:53.104] Jiman afflicted by Instability (11) from Jiman
[20:16:54.962] Jiman's Instability fades
[20:16:54.962] Jiman's Unchained Magic fades
[20:16:54.962] Jiman gains Ice Block from Jiman
[20:16:55.300] Jiman's Ice Block fades
[20:16:55.406] Jiman Backlash Jiman 19206 (R: 2200)

Looks like you need to wait around a half a second before clearing the ice block.

Like the poster a few posts above me, I understand the standard rotation as 4ab/mbAM or you fish until you proc for mbAM. I've found it's not really sustainable in the longer fights (mostly when I get unlucky). If I have to clear my stacks, should I be using AB or AM? I've been told both answers from asking around. My Rawr shows AB as doing more DPS than AM. I don't know if that's how I should be interpreting it though in terms of mana efficiency or other factors.

If we are very lucky and proc MBAM every 4 ABs or less our mana depletes very slowly, almost to the point where its a non-issue. The only real mana issues arise when we are forced to fish for MBAM past the 4th AB. This is a double edged sword because we are doing relatively high DPS, but burning through our mana.

To answer your question about clearing stacks:

-ABarr is higher DPS than AM
-AM is higher DPM than ABarr
-ABarr can be cast on the move and might proc MBAM
-AM allows for more passive regen during the cast time than ABarr

So you have to make a choice based on the situation.

EDIT:
@Wizeowel

You are correct, that in the long run, casting AM to break stacks will be higher DPS because of the 40% chance to proc MBAM. 40% of the time when you are casting "blind" you will win and MBAM will proc. What i said only holds true if MBAM does not proc and you end up casting an unhasted AM that costs mana.

How do I check if I perform better with a [nochanneling] macro for arcane blast or without? Random crits probably make the dps on training dummies unreliable.
Should I use some addon like Gnosis - Addons - Curse , and how? Thanks

So our guild just cleared sindragosa and started to work on lich king. I wanted to ask a couple questions to help improve myself.

1. What dps rotation do you suggest for arcane when you have unchained magic and ice block is on cd. Obv, if you have iceblock up and your cooldowns, you can just burn your normal rotation and then iceblock before air phase, but what about when you can't iceblock? Should I rotate arc blast and arc missile to minimize stacks (say, cast 8 or 10 spells for 4-5 stacks(assume I have the latency to pull that off)) or should I go through one normal rotation, perhaps AB5MBAM? I suppose a related question is how high I should build my stacks during phase 1 as compared to phase 3?

2. On the lk fight, should I spec something specific? Perhaps fire/ffb for phase 3? Or perhaps spec slow to help with the valks?

Speccing for Lich King is going to be based on what the rest of your raid can do, if Val'kyr are a problem because they aren't being snared then look into speccing slow, if Vile Spirits are destroying the raid then likewise look into a Living Bomb spec. It all depends on your raid comp and how the other 24 people handle themselves.

My advice (though somewhat unhelpful) would be to play it by ear, spec into whatever utility will make the fight smoother for the guild.

I've had the best luck on Cindragosa, when IB is on CD, doing a 2AB1AM rotation. Reviewing logs afterwards, I had no noticeable DPS loss compared to rolling a standard 4ABMBAM rotation. If MBAM procs, I'll cast 2 AMs. The reasoning behind this is that with 1100 haste, plus raid buffs, you will only have to pause casting for a fraction of a second between the final AM and the first AB of the next cycle, minimizing downtime. Rolling 2AB1AM guarantees no more than 4 stacks of the debuff, which my guild's healers have told me is trivial. You could stretch it to 3AB1AM (2AM if MB procs) if you aren't taxing your healers, or dumb it down to 1ABM1AM if you are (although if four stacks is taxing your healers on normal, I would question their ability to heal Valithria).

I am assuming that you do this with pushback resistance, and that you don't often get lucky chains of missile barrage procs. I'm not sure why this would have any benefit over a regular 4AB1AM rotation. In both cases, if you get a missile barrage proc, you'd have to wait out the 4 seconds anyway. Since AM is a channeled spell and you cast it immediately following the final arcane blast, it doesn't give you a an extra debuff.

Comparing your suggestion of 2AB1AM to this, it would seem like you are getting similar number of debuff stacks (4 stack per 12.5-15 seconds of unhasted cast time), but doing less DPS overall. The only benefit seems to be having smaller 2 stack debuffs explode twice as often. Since a 4 stack debuff isn't anywhere near dangerous anyway, I'm not sure why you'd do it. You'd also get pushback more frequently.

Yes, I have full pushback resistance between my spec, and a pally running their aura. Lucky chains of MB procs has nothing to do with it. Thats why I have given the breakdown I have; it removes a hasted AM from the equation without gimping DPS or creating unnecessary stacks. There is no waiting 4 seconds in the sense of just standing there; you are actively casting during 3.6 of those 4 seconds without gaining a stack to refresh the debuff.

I think you may have misread what I said. I'll rephrase, to make it a more general statement. xAByAM. x is how many stacks you can comfortably push with your raid healing setup, as well as what phase you're in. y is 1 if you don't get an MB proc, and 2 if you do. As I said, the DPS loss is negligible (in fact, unnoticeable). The reason for rolling 2/3AB1/2AM rather than a full rotation is two-fold. First, to help the healers on what may be a hectic fight, especially on heroic. Every healer I've talked to would rather heal a little bit of damage more often than have to heal one huge chunk of damage taken instantly. Second, by keeping better control of your stacks, you are less likely to die if you get frost tombed. The Suffocation debuff sucks, but when you take a big punch to the face from Unchained Magic, it sucks even more.