|HastedCastTime = BaseCastTime /(1 + (% SpellHaste / 100))|
1.5s /(1 + (10 / 100)) = 1.3636s
GCD or 1.5 second cast with the full GotEM3.3 will become:
- A Nature's Grace proc will move the GCD from here to 1.14 seconds
- Wrath of Air totem alone will make it 1.30 seconds
- Improved Moonkin or Imp. Ret auras alone will make it 1.32 seconds
- Bloodlust alone will take it to 1.15 seconds
- WoA totem + Imp. aura will make it 1.26 seconds
- A Nature's Grace Proc on top of the totem+aura stack will make it 1.05 seconds, pretty much the minimum GCD limit... 166.34 haste rating from there will cover that 0.05 seconds. This also applies to nourish (and glyphed but untalented HT), as the GotEM3.3 10% haste applies to ALL spells!
What this does mean, though, is that it will take 1192 spell haste rating to get yourself down to a 1.0 second GCD, sans any raid buffs (including the auras and totem and NG procs). 1193 will push you just over the minimum GCD to 0.9998... which will effectively cap at 1.0 seconds.
WoA + Aura Buff
With a stack of WoA totem + improved aura from moonkin or ret pally, you will "only" need 855.4 haste rating from gear to reach a 1.0 sec GCD/Nourish cast. Such numbers may be achievable around the time of T11 gear (without overly gimping other stats, including crit)... though of course, any bloodlust will send you straight to the GCD cap, as will NG procs.
WoA + Aura buff + NG
Adding in a reliance on Nature's Grace procs (which themselves rely on crit rating), you can lower this all the way down to 166.34 haste rating. Most raiding druids already have this amount of haste rating, but fewer can rely on NG procs due to being purely raid healers. This will be more useful to druids who focus on MT-healing through Nourish or HT (though do note that this only requires the HT glyph, and not the Naturalist talent, as a combination of both will automatically put you at the minimum 1-second GCD with or without both GotEM and haste gear), assuming they can gear up in appropriate crit gear and cast frequently enough to keep NG active. Any lull in spell crits will push their GCD back to 1.2 seconds.
Fun times. Will post up graphs of the haste ratings to GCD, once I double-check them and make them pretty :) Edit: graphs are here.
~~If there are any flaws in my math, please feel free to point them out... I spreadsheeted it out kinda quick in free time between pulls during a raid tonight!~~