Mana regen: INT as *the* mana regen stat?

[Kaysha]

I've seen numerous posts around these forums, stating that Intellect is *the* mana regen stat for Priests. Somehow, those numbers don't really make sense to me. Maybe it's because I'm a Holy priest, but to me it feels like Spirit is better for mana regen than Intellect. So I have done some number crunching on it.

I've been pretty much of a Spirit junky, because it gives both spellpower and mana regen, so that's what I aimed my gems and enchants for. Of course, I am assuming that a Holy priest has the Spirit of Redemption talent, as well as the Spiritual Guidance. Also, Meditation in the Discipline tree seems just about mandatory for a Holy priest.

The base formula (as grabbed from WOWwiki):
MP5 = 5 * (0.001 + sqrt(Int) * Spirit * Base_Regen) * 0.60, where base regen at lvl 80 is 0.005575.

I will use my own stats here. These are totally unbuffed (but gear fully gemmed and enchanted, aiming at Spirit over Intellect):
INT = 1177
SPI = 1252
SP = 2331, of which 2018 comes from straight Spellpower on gear, and 313 from Spirit.
MP5 = 920 / 561, of which I gain 718 / 359 from the amount of Spirit and Intellect I have. I have 202 straight MP5 on my gear.
Mana = 21238

Now, as said, I have gemmed for Spirit mostly, over Intellect. Of the above values, I have 71 INT, 130 SPI (120 base, but boosted by Human Spirit (3%) and Spirit of Redemption (5%)) and 12 SP from gems. If I were to swap these out for Intellect mostly, over Spirit, I would gain 90 INT and 12 SP and lose 108 SPI (100 SPI from gems, but boosted). For good measure, I will also assume to swap out my +100 SPI trinket for the +128 INT one. This drops me another 108 SPI effectively.

Altering these values and plugging them into the MP5 formula I stated above, the values change as follows:
INT = 1267
SPI = 1036
SP = 2273 (2018 from straight Spellpower on gear, 255 from Spirit)
MP5 = 849 / 525 (647 / 323 from SPI and INT)
Mana = 24508

So that's a loss of 71 / 36 MP5 and 58 SP, while gaining 3270 mana in the initial pool. Assuming that regen happens outside the FSR, 3270 mana is regenerated in just under 4 minutes. Inside the FSR, it's regenerated in just over 7,5 minutes. Over an entire battle, it's likely to be partially inside the FSR, partially outside (if for nothing else than because of the mechanics of a boss encounter that enforces this). As such, shorter fights benefit more from the Intellect, while longer fights benefit more from Spirit.

Tonight we did ToC10 again and I checked the fights; most of them lasted on average around 6 minutes from start to finish. I don't have exact time data on other fights (like in ICC10, or Ulduar10 ... I have no experience in 25-man raids to those locations), but my feeling says they're not much different. Of course, I am not considering specific fights like against General Vezax, as mana regen is blocked there.

Based on this data, I conclude that chosing for INT over SPI or vice versa is pretty much personal taste, but that's only because INT increases the mana pool. As a plain mana regen stat, it is (much) worse than SPI. The main reason, of course, is that mana regen goes up with the square root of INT, while it goes up linear with SPI. So, a point of INT contributes less than a point of SPI and the higher the INT goes, the less the overall contribution from a single INT point becomes.

Or am I missing something in the scheme of things that calls INT the best mana regen stat?

[Pumaska]

Int is actually better for 1 simple reason: Replishment

[Kaysha]

Ah, yes, that's a source I had not considered as it's an external source. Also, I have to admit I never really did the numbers on that one.

As Replenishment is 1% of maximum mana every 5 seconds, this leads to an effective MP5. In my case, using both mana pool sizes, this would amount to 212 MP5 (high SPI case), or 245 MP5 (high INT case). A difference of 33 MP5.

Hmm, interesting. I will have to check how often I have Replenishment up during boss fights.

Thanks for that info.

[fabian]

Int is actually better for 1 simple reason: Replishment

Well, not 1 simple, more like many reasons: SF, HoH, Mana Tide, and a bigger mana pool.

[Kaysha]

Well, not 1 simple, more like many reasons: SF, HoH, Mana Tide, and a bigger mana pool.

I cannot really count on Mana Tide, as we have no real active Shamans in our Guild (and we're not a raiding guild, so we are not specifically recruiting Shammies either ). Shadow Fiend is useful once during most fights as you won't be casting it right from the start and it will still be on cooldown when the fight ends. I think I've had perhaps just one or two fights where I used it twice. But still, it's a factor to consider, as is Hymn of Hope. I will do some numbers on those too.

But I find HoH to be situational at best. Since many fights seem to ramp up the DPS as time passes, often I cannot spare the time to cast it.

[ohlins]

If u want the regen: intellect
If u want both regen and troughput: spirit (as a HOLY priest)
If u want troughput: SP.
Its a personal matter and what u feel comfortable with.

[Antegon]

As a priest, besides the above listed things that return mana based on int... Your shadow fiend does as well. That is why priests these days chain their Fiend and Hymn together, a single tick of hymn ups your mana pool causing fiend to return more as well.

[Danner]

You are indeed missing two factors, Kaysha.

-----

First of all, intellect is a very powerful regen mechanic in its own right thanks to active and passive abilities working off max manapool size. 1 int gives 15 mana, and this in turn makes all those abilities stronger. Assuming all these are at 100% uptime or used at every cooldown:

Replenishment: 0.15 MP5 per point of intellect
Shadowfiend: 0.125 MP5 per point of intellect (much more if used with Hymn of Hope or Bloodlust)
Manatide totem: 0.06 MP5 per point of intellect (per manatide, stacks)
Hymn of Hope: 0.06 MP5 per point of intellect, but stacks exponentially if used with more than one
Arcane Torrent (if blood elf): 0.02 MP5 per point of intellect
...

This is easily 0.35 MP5 per point of int from these abilities alone, assuming you actually use them all. But lets be frank. You won't; these abilities will not be used at every cooldown. Even replenishment will not be up 100% of the time. But even at 80% average usage, add that to the gains from int from your formula, and you will see that intellect is a very strong contender to spirit. For a holypriest, 1 spirit is worth ~0.5 MP5 (my rule of thumb, your reality may differ). Int is about the same value by doing this calculation, adding the gains from the spirit formula and the active cooldowns together.

Of course, spirit gives a decent amount of spellpower as well, which is much better than the crit gained from int. So if this was all there was to it, spirit would still be better.

-----

The second gain from intellect is the actual manapool increase itself. And this is the real killer argument for intellect. Intellect vastly increases your short-term manapool, but it doesn't do much for your longterm manapool.

If the fight lasts 1 minute, 1 MP5 will give you 12 mana. In comparison, you could get 2 intellect = 30 max mana for the same itemization price. In this case, intellect is superior

If the fight lasts 5 minutes, 1 MP5 will give you 60 mana. This is now superior to the 30 mana you gained earlier.

At a fight lasting an infinite amount of time, the gains from having a large starting manapool is nil compared to having actual regen. But you are not fighting forever! Dont aim to heal forever, you will never have to. Bosses enrage after 10-15 minutes anyway. Your DPSers will usually suck if they can't down the boss in 8 minutes.

The breaking point is at a fight lasting 2.5 minutes. At this point, having a larger manapool or having the itemization as MP5 does not matter, you will get the same.

Most (all?) fights definitively last more than 2.5 minutes. But at the same time, very few fights last less than 7.5 minutes. Let's assume this as our common case, and claim that all fights last 7.5 minutes. This means I can claim that the initial mana given to me by intellect is worth exactly a third of what given to me by MP5.

Or basically, 1 int is worth 0.5 MP5 / 3 = 0.16MP5. This is "fake" income you get by having a large starting pool. It's not real income, its just reserves we're draining from. If the fight lasts 7.5 minutes, having that mana as actual regen or reserves does not matter.

This 0.16 MP5 is quite a lot. It's actually better than replenishment if you compare it directly (replenishment is worth 0.15 MP5 assuming 100% uptime). Add this to the ~0.5 MP5 I gained from 1 intellect in the previous section, and we're now way up to 0.66 MP5 per point of intellect.

As holy. Discipline will get a lot higher due to their intellect coefficient talent, but then again no discpriest is interested in stacking spirit anyway.

[Lucablight]

i stack both pretty evenly, trying to keep the two between 100 points, it has been working well.